All living organisms are made of organic molecules containing Carbon (C). These large molecules (polymers) are built from smaller, simpler subunits (monomers).
In living organisms, metabolism must happen very quickly to maintain life processes like respiration, digestion, and excretion. At normal body temps., these reactions would occur far too slowly to sustain life.
Enzymes lower the activation energy required for these reactions, allowing them to happen fast enough to keep organisms alive.
Enzymes are highly specific. This means one enzyme can only catalyze one specific reaction.
The reason for this is entirely due to the complementary shape of the active site. If the substrate’s three-dimensional shape does not perfectly match the fit of the active site, no enzyme-substrate complex can form, and no reaction will occur.
Very slow rate. Low frequency of effective collisions between enzymes and substrates.
Rising temps.
Kinetic energy increases. Molecules move faster.
Rate increases. The frequency of effective collisions increases.
Optimum temp.
The temp. at which the enzyme works at its maximum possible rate (approx. 37°C in humans).
Peak reaction rate.
High temps.
Excessive thermal energy breaks the weak bonds holding the protein structure together.
Rate drops rapidly to zero. The enzyme is denatured.
When an enzyme denatures, the shape of its active site is permanently altered. The substrate can no longer fit into the active site, meaning no effective collisions can happen and the reaction stops.
Every enzyme has an optimum pH where it functions best. For most cellular enzymes, this is around pH 7 (neutral), but there are exceptions (e.g. pepsin in the acidic stomach works best at a low pH, like pH 2).
Going too far or below the optimum pH alters the chemical bonds within the enzyme protein, resulting in the change of the shape and fit of the active site. This is denaturation.
Large surface area maximizes the absorption of sunlight and provides a larger area for carbon dioxide to diffuse out the leaf.
Its thinness creates a very short diffusion distance for carbon dioxide to travel from the air spaces to the photosynthesizing cells, and allows light to penetrate completely through the leaf.
Forms a network of large air spaces that allow gases (carbon dioxide and oxygen) to diffuse rapidly between the stomata and the palisade cells.
Air spaces
Large gaps between the cells of the spongy mesophyll layer.
Increases the internal suface area for efficient gas exchange and allows carbon dioxide to circulate freely.
Lower epidermis
The bottom layer of protective cells on the leaf.
Contains the majority of the guard cells and stomata to regulate gas exchange while minimizing water loss from the shaded underside.
Stomata (sg. stoma)
Tiny pores or openings found mostly in the lower epidermis.
Act as the entry and exit points for gases; allows carbon dioxide to diffuse into the leaf and oxygen(plus water vapour) to diffuse out.
Guard cells
Pairs of specialized epidermal cells surrounding each stoma.
Control the opening and closing of the stomata. They open during the day to allow carbon dioxide entry for photosynthesis and close at night (or during drought) to conserve water.
Vascular bundle
The transport system of the leaf, containing the xylem and phloem.
Provides structural support to keep the leaf blade flat and well-positioned to cattch sunlight, while containing the transport vessels.
Xylem
Thick-walled, dead vessels found in the upper part of the vascular bundle.
Transports water and dissolved mineral ions from the roots up to the leaf cells. Water is a direct raw material for photosynthesis.
Phloem
Living transport tissue found in the lower part of the vascular bundle.
Transports sucrose and amino acids made from the products of photosynthesis away from the leaf to growing regions or storage organs (translocation).
Chloroplasts
Organelles concentrated mainly within the mesophyll layers.
Contain chlorophyll to trap light energy and convert it into chemical energy for synthesizing carbohydrates.
As light intensity increases, the rate of photosynthesis increases proportionally. Light energy is providing the power for the reaction.
At a certain point, the graph plateaus. Further increases in light intensity do not increase the rate. This means light is no longer the limiting factory; either temperature or carbon dioxide concentration is in short supply.
Before running these tests, the plant must be destarched by placing it in a dark cupboard for 48 hrs. so it uses up its stored starch.
Destarching is the process of removing stored starch from the leaves of a plant before running a photosynthesis experiment.
Chlorophyll: Use a variegated leaf(a leaf that has more than one color, usually appearing with green parts and white or pale yellow parts, occurs because chlorophyll is not distributed evenly across the leaf). Only the green parts will turn blue-black witth iodine.
Light: Cover part of a destarched leaf with aluminium foil and expose it to light. Only the uncovered areas will test positive for starch.
Carbon dioxide: Place a plant inside a sealed bag with soda lime(to absorb carbon dioxide). The leaves will test negative for starch because no carbon dioxide was available for the plant to photosynthesize.
Hydrogencarbonate incdicator is sensitive to pH changes caused by changes in carbon dioxide concentration (dissolved carbon dioxide forms a weak acid).
Atmospheric carbon dioxide levels (equilibrium): Red
High carbon dioxide levels: Yellow (indicates respiration is happening more than photosynthesis, or it’s dark).
Low carbon dioxide levels: Purple (indicates rapid photosynthesis is consuming carbon dioxide faster than respiration produces it).
Absorption is the movement of small, digested food molecules and ions through the walls of the intestine into the blood or lymphatic system.
The small intestine is where nutrients are absorbed.
A common misconception is that water is only absorbed by the large intestine. Most water is actually absorbed in the small intestine alongside dissolved nutrients. The colon (large intestine) also absorbs some of the remaining water to compact undigested material into solid feces.
To absorb massive quantities of nutrients efficiently before food passes out of the body, the small intestine requires a huge internal surface area. This is achieved through thousands of finger-like projections called villi(sg. villus).
The villi are folds in the inner lining (mucosa) of the small intestine. They multiply the inner surface area by a factor of many hundreds.
The microvilli are microscopic foldings on the cell surface membranes of the individual epithelial cells that cover each villus.
By having both villi and microvilli, the small intestine dramatically increases its surface area : volume ratio. This structural adaption ensures a significantly faster rate of diffusion and active transport, allowing nutrients to move out of the gut cavity and into the bloodstream as quickly as possible.
The outer layer of the villus is only one cell later thick, providing a short diffusion distance for food molecules to pass through, accelerating the rate of absorption.
A rich network of microscopic blood vessels runs directly beneath the epithelium.
They absorb water, soluble carbohydrates (glucose), amino acids, mineral ions, and water-soluble vitamins.
The continuous flow of blood rapidly carries these absorbed nutrients toward the liver (via the hepatic portal vein), maintaining a steep concentration gradient so diffusion can continue uninterrupted.
A small tube located right in the center of the villus, which is a part of the lymphatic system.
Lipids (fats and oils) are too large and hydrophobic to safely enter standard blood capillaries directly. Instead, digested fatty acids and glycerol are recombined into small fat droplets inside the epithelial cells and absorbed straight into the lacteal. The lymphatic system later empties these lipids into the main bloodstream.
Large food molecules (e.g. starch, proteins, lipids) are polymers that are physically too big to cross the cell membranes of the epithelium lining the alimentary canal.
Chemical digestion breaks the covalent bonds within these polymers, turning them into tiny, soluble monomers (e.g. glucose, amino acids).
Once they are small and soluble, they can dissolve in the watery fluids of the digestive tract, pass through the walls of the small intestine, and enter the blood capillaries or lacteals to be transported around the body.
Killing harmful microorganisms. The extreme acidity denatures the enzymes and structural proteins of bacteria and other pathogens present in swallowed food, protecting the body from infection.
Providing an optimum acidic pH. The main protease enzyme in the stomach requires a highly acidic environment to change into its active shape and catalyze the breakdown of proteins efficiently.
Starch cannot be broken down into glucose all at once. It requires a precise two-step biochemical pathway.
Amylase breaks down starch into maltose. This occurs via salivary amylase in the mouth and pancreatic amylase in the duodenum.
Maltase breaks down maltose into glucose. This enzyme is located on the membranes of the epithelium lining the small intestine, ensuring glucose is produced directly at the surface where it can be immediately be absorbed.
$\text{Starch} \xrightarrow{\text{Amylase}} \text{Maltose} \xrightarrow{\text{Maltase (on epithelium)}} \text{Glucose}$
Proteins are digested by two different types of protease enzymes that are structurally adapted to function at opposite ends of the pH scale.
Pepsin, site of action is the stomach.
Requires acidic conditions(provided by HCl) to function safely without denaturing. It breaks long protein chains down into smaller polypeptide fragments.
Trypsin, site of action is the duodenum (small intestine).
Secreted by pancreas as part of pancreatic juice. It breaks down the polypeptides into individual, fully soluble amino acids, but it requires alkaline conditions to function.
Bile is an alkaline mixture that neutralizes the acidic mixture of food and gastric juices entering the duodenum from the stomach, to provide a suitable pH for enzyme action.
A balanced diet is a diet that contains all the essential nutrients in the correct proportions and right quantities needed to maintain health, growth, and development.
A balanced diet must include:
enough energy(provided by carbohydrates, fats, and proteins)
essential amino acids from proteins
essential fatty acids from fats
micronutrients(vitamins and minerals)
water to replace water lost in urine, sweat, breath and feces
fibre for moving food from the mouth to the anus along the gut.
If eaten in the correct proportions, these components make up a balanced diet which is a healthy diet.
Mechanical digestion: Teeth chew and break food into smaller pieces (increasing surface area)
Chemical digestion: Saliva containing the enzyme amylase begins breaking down starch into maltose.
Oesophagus
Function: A muscular tube connecting the mouth to the stomach. It moves the bolus downward via peristalsis.
Stomach
Function: A muscular bag where about 1L of food (but can stretch to accommodate more) is held for a few hours.
Mechanical digestion: Churns and squeezes food into a liquid called chyme.
Chemical digestion: Secretes gastric juice containing protease (pepsin) to break down proteins into peptides. It also secrets hydrochloric acid which kills harmful bacteria and provides the optimum acidic pH (pH 1.5-2.0) for pepsin to work.
Small intestine, divided into two main parts: duodenum and ileum.
Function of duodenum (first part): Main site of chemical digestion. Enzymes from the pancrease and bile from the liver are released here to complete the breakdown of large molecules.
Function of ileum (second part): Main site of absorption. Highly adapted for moving digested nutrients (glucose, amino acids, fatty acids) out of the intestine and into the bloodstream. It has a massive surface area covered in microscopic, finger-like projections called villi.
Large intestine, divided into the colon, rectum, and anus.
The colon is responsible for the absorption of remaining water from undigested material, turning liquid waste into semi-solid feces.
The rectum stores the feces temporarily until they are ready to be expelled.
The anus is a sphincter muscle controlling egestion; it relaxes to remove undigested food from the body as feces.
Salivary glands secrete saliva into the mouth to lubricate food and release amylase.
The pancreas secretes pancreatic juice into the duodenum. This juice contains a cocktail of digestive enzymes:
amylase for carb. digestion
protease/trypsin for protein digestion
lipase for fat digestion.
NaHCO to neutralize stomach acid.
The liver produces bile, which neutralizes stomach acid and emulsifies fats. The liver is also heavily involved in assimilation, where it sorts, processes, and stores nutrients arriving from the blood via the hepatic portal vein (e.g. converting excess glucose to glycogen, or deaminating excess amino acids).
The gall bladder is a small storage sac that stores bile produced by the liver before releasing it into the duodenum via the bile duct.
The enamel is the extremely hard, outer layer covering the crown (visible part) of the tooth. It contains calcium salts and is the hardest substance made by the human body. It protects the tooth from the mechanical wear and tear of chewing.
The dentine(labeled as dentin) is the layer directly beneath the enamel. It forms the bulk of the tooth structure and is similar in texture to bone but slightly softer than enamel.
The pulp cavity is the central living region of the tooth. It contains blood vessels(to deliver nutrients and oxygen to the tooth cells) and nerves(to detect pressure and temp. changes).
The cement is a specialized bone-like substance covering the root of the tooth. Itt helps anchor the root firmly to the surrounding fibers within the jawbone.
When the mouth starts physical digestion, the stomach continues it mechanically through churning.
The stomach wall contains three strong layers of smooth muscle oriented in different directions. These muscles periodically contract and relax, rhythmically squeezing, pounding, and mixing the food with gastric juices.
This mechanical action breaks the solid bolus down into a thick, semi-liquid mixture called chyme, maximizing its exposure to stomach acid and pepsin.
Bile is produced by the liver and stored in the gall bladder. It does not contain enzymes, so its action is entirely physical.
When bile enters the duodenum, it breaks down these big, greasy fat globules into millions of tiny microscopic droplets.
This physical process is called emulsification.
Emulsification does not break any chemical bonds within the lipids. Instead, it drastically increases the total surface area of the fats and oils, giving the enzyme lipase vastly more physical space to bind and rapidly digest lipids into fatty acid and glycerol.
Translocation is the movement of sucrose and amino acids (in phloem) from the leaves (sources) to regions of respiration, growth and storage (sinks).
Unlike transpiration which is a passive process driven by the evaporation of water, translocation is an active process. It requires metabolic energy from the plant’s living phloem cells to move dissolved nutrientts (sap) throughout the organism.
Transport in translocation is bidirectional, where it can move up or down the plant depending on where the materials are needed.
The leaves are the SOURCE. The leaves are fully developed and photosynthesizing rapidly. They produce far more glucose (converted to sucrose) than they need.
The roots/tubers are the SINK. The excess sucrose is sent downward to the roots or underground storage organs (e.g. potato tuber) where it is converted into insoluble starch and stored for the winter.
The roots/tubers become the SOURCE. The plant has lost its leaves over winter and cannot photosynthesize. To grow new leaves, it must break down the insoluble starch stored in its roots/tubers back into soluble sucrose. The roots release this sucrose into the phloem.
The new buds/leaves become the SINK. The newly forming buds and young leaves absorb this sucrose from the phloem, using it for cellular respiration and rapid growth until they are mature enough to photosynthesize on their own.
Transpiration is the evaporation of water at the surfaces of the mesophyll cells, followed by the diffusion of water vapour through stomata to the atmosphere.
Water molecules gain more kinetic energy, increasing the rate of evaporation from mesophyll cells. Increases molecular movement, accelerating diffusion out of stomata.
High wind speed
Increases
Moving air blows away the escaped water vapour accumulating just outside the leaf surface. This maintains a steep concentration gradient between the inside and outside of the leaf.
Humid
Decreases
High humidity means the air outside the leaf is already saturated with water vapour, flattening/reducing the concentration gradient, slowing down diffusion.
A potometer is used to measure the rate of water uptake (which is closely equal to the rate of transpiration).
Function: As the leafy shoot transpires, it draws water from the capillary tube. This moves an air bubble along a scale. By measuring the distance the bubble travels in a set amount of time, you can calculate the rate of transpiration.
Varying conditions in an experiment:
Testing temp.: Place the apparatus under a heat lamp or in rooms of different temps.
Testing wind speed: Place a fan at varying distances or speed settings next to a plant.
Large internal surface area: The spongy mesophyll layer contains a vast network of interconnecting air sppaces. This creates a highly maximized internal surface area for water to evaporate into, accelerating the rate of water vapour accumulation.
Size and number of stomata: Leaves with more stomata or wider stomatal openings provide more exit pathways, increasing the rate of diffusion out of the leaf.
Transpiration pull is when water moves upwards in the xylem and this pull draws up a column of water molecules, held together by forces of attraction between water molecules.
Cohesion: Water molecules tend to attract each other, sticking together and moving upwards together.
Adhesion: The water molecules tend to stick to the inside of the xylem vessel so reducing the chance that the columns of water will be broken.
Continuous column: Since water molecules cohere strongly, they form an unbroken, continuous column of water stretching all the way from the roots, up through the xylem in the stem, and into the leaves.
The water loss (or transpiration) > water uptake causes a water deficit which then causes wilting.
Water moves out of vacuoles of plant cells. These cells lose their internal fluid pressure and change from being turgid to flaccid.
Without this turgor pressure pushing against the rigid cell walls, the cells can no longer mechanically support the plant’s weight. The leaves and stem droop downward.
Once water enters the root hair cell, it travels down a water potential gradient across the plant tissues. The exact sequence of structures it passes through is:
**Water in soil ** $\rightarrow$ Root hair cells $\rightarrow$ Cells of cortex $\rightarrow$ Xylem $\rightarrow$ Mesophyll cells
Root hair cells: Water enters from the soil by osmosis because the cytoplasm of the root hair cell has a lower water potential than the surrounding soil water.
Root cortex cells: Water moves from cell to cell across the root cortex via osmosis until it reaches the central vasuclar cylinder.
Xylem: Water enters the hollow xylem vessels, where it is pulled upwards throught he stem to the leaves by the transpiration stream.
Mesophyll cells: Once in the leaves, water leaves the xylem and moves into the surrounding mesophyll cells, where it is used for photosynthesis or evaporates into the air spaces before transpiring out through the stomata.
In the stem, there are distinct colored dots arranged in a ring. They are the xylem vessels within the vascular bundles, demonstrating that water travels up the stem specifically through the xylem.
In the leaves, the colored dye will eventually spread into the veins, highlighting the continuation of the vascular system from the stem into the leaves.
Vascular tissues are responsible for mass flow transport over long distances within a plant. They are split into two distinct systems:
the xylem, which transports water and mineral ions from the roots up to the leaves and provides structural support to the plant due to its rigid walls
transportation is in one direction only. from roots via stem to leaves
the phloem, which transports sucrose and amino acids from the source (where they are made or stored, like leaves) to the sink (where they are used or stored, like roots, flowers, and growing tips).
Xylem vessels are highly specialized dead cells that form a continuous piping system. Their structures directly enable efficient water transport.
Feature
Relating to function
Thick walls with lignin
Lignin makes the cell walls storng and waterproof, preventing vessles from collapsing inward under the extreme pressure (tension) created by transpiration, while also offering support to keep the plant upright.
No cell contents
The cells are dead and completely empty (no cytoplasm, nucleus, or organelles). This leaves a completely hollow central space (lumen) so water can flow freely with minimal resistance.
Joined end-to-end with no cross walls
Individual cells break down their end walls where they meet to form a long, continuous tube. This allows water columns to travel uninterrupted from the deepest roots all the way to the top of the leaves at the top.
the heart pumps blood into arteries in high-pressure surges. To withstand this without bursting, arteries have thick, reinforced walls.
To maintain this presure between heartbeats, their walls contain elastic fibers that stretch when blood surges and recoil to push the blood along.
For veins:
by the time blood reaches the veins, it has lost most of its pressure. Since the pressure is low, thick walls are unnecessary; instead, veins have a wide lumen to minimize resistance and help blood flow easily back to the heart.
Because blood moves slowly under low pressure, veins require valves to prevent the backflow of blood due to gravity.
Capillaries do not only transport blood, but they are the sites of material exchange between the blood and body tissues.
They allow the exchange of oxygen, glucose, carbon dioxide, nutrients, and waste products between blood plasma and the surrounding tissue cells.
Their walls are made of a single layer of endothelial cells(flat cells that form the inner lining of blood vessels). This feature provides an extremely short diffusion distance, allowing substances to move into and out of tissues rapidly.
Capillaries form vast, intricate networks through every tissue in the body, providing a massive total surface area for efficient diffusion.
The lumen is so tiny that red blood cells must squeeze through in a single-file line. This slows down the blood flow for maximum time for gas and nutrient exchange to occur.
Hepatic artery: Supplies oxygenated blood directly from the aorta to the liver tissue to fulfill its high oxygen demands.
Hepatic vein: Carries deoxygenated blood from the liver back to vena cava.
Hepatic portal vein: An important vessel. It carries nutrient-ricj blood directly from the digestive tract (stomach and intestines) straight to the liver.
This allows the liver to sort, store, or detoxify absorbed nutrients before they are distributed to the rest of the body.
Oxygen transport from lungs to respiring tissues. They contain hemoglobin, an iron-rich protein that binds reversibly to oxygen to form oxyhemoglobin.
Phagocytes
Protect the body by engulfing and digesting pathogens (bacteria/viruses) via a process called phagocytosis.
Lymphocytes
Protect the body by producing antibodies. These proteins bind to antigens on pathogens, clumping them together or marking them for destruction by phagocytes.
Platelets
Responsible for initiating the blood clotting process when a blood vessel is damaged.
Plasma
Liquid that serves as the transport medium for blood cells, ions, nutrients (glucose, amino acids), waste products (urea and carbon dioxide) and hormones.
Activating platelets: Damage to the blood vessel lining exposes collagen fibers, causing platelets to adhere to the site and release clotting factors.
Protein conversion: These factors trigger a process that converts a soluble plasma protein called fibrinogen into an insoluble fibrous protein called fibrin.
Mesh formation: The fibrin strands stretch across the damaged area, forming a sticky, microscopic mesh.
Trapping cells: Red blood cells and additional platelets flowing past become trapped within the fibrin mesh, forming a solid plug (clot) that later hardens into a scab.
In mammals, blood passes through the heart twice for each complete circuit of the body. It is split into two distinct loops.
Pulmonary circuit, heart to lungs to heart. The right side of the heart pumps dexoygenated blood to the lungs to pick up oxygen and release carbon dioxide. The oxygenated blood then returns to the left side of the heart.
When the heart pumps blood to the lungs, there is low pressure required, resulting in little resistance. The reasons why are because:
the distance from heart to lungs is short
the low pressure is also important to protect the delicate lung tissue, and the capillaries are only one cell thick for efficient diffusion, which can be ruptured if the heart pumped at high pressures.
Systemic circuit, heart to body to heart. The left side of the heart pumps this oxygenated blood at high pressure to the rest of the body organs. Deoxygenated blood then returns to the right side of the heart.
Atria(sg. atrium): The two upper chambers. Thin walls and receive blood entering the heart from the veins.
Ventricles: Two lower chambers. They have thick muscular walls and pump blood out of the heart into the arteries
Septum: A solid wall of muscle that separates the left and right sides of the leart.
It prevents oxygenated blood (left side) from mixing with deoxygenated blood (right side), ensuring the body receives the maximum possible concentration of oxygen.
Valves: Flaps of tissue that keep blood flowing in one direction.
Atrioventricular (AV) valves: Situated between the atria and ventricles. They stop blood from flowing back into the atria when the ventricles contract.
Semilunar (SL) valves: Found at the entrances to the pulmonary artery and aorta. They prevent blood from flowing back into the ventricles when the heart relaxes.
Coronary arteries: A network of blood vessels running across the outside of the heart. They branch off the aorta to supply the heart muscle tissue itself with its own constant supply of oxygenated blood and glucose.
Blood is pumped AWAY FROM the heart by the ARTERIES.
Atria only need to pump blood a very short distance (just down into the ventricles). Ventricles must pump blood out of the entire heart to the lungs or body.
Left vs. right ventricle
Left ventricle wall is significantly thicker than the right ventricle wall.
The right ventricle only pumps blood to the lungs(a short distance, requiring low pressure to protect delicate tissues). The left ventricle must pump blood to the entire rest of the body, overcoming high resitance and requiring much higher pressure.
When you exercise, your muscles contract much more frequently and powerfully.
Active muscles require a significantly higher amount of energy, which they release via aerobic respiration.
To sustain this, the muscles need an increased supply of oxygen and glucose. They also produce carbon dioxide waste much faster, which must be removed.
The brain detects the increase of carbon dioxide in the blood and signals the heart to beat faster and contract harder (increasing stroke volume). This speeds up blood circulation to fulfill the metabolic demands of the working tissues.
Diet: Consuming high amounts of saturated fats and cholesterol increases plaque buildup.
Lack of exercise: Weakens the heart muscle and contributes to high blood pressure and obesity.
Smoking: Nictonie constricts blood vessels and damages their linings, making plaque buildup more likely. Carbon monoxide reduces the blood’s oxygen-carrying capacity.
Stress: Releases hormones that chronically elevate blood pressure, putting strain on the arteries.
Genetic predeposition: A family history of cardiovascular disease can mean naturally higher blood pressure or cholesterol levels.
Age: The risk increases naturally as blood vessels lose their elasticity over time.
Sex: Males statistically face a higher risk than pre-menopausal females due to the protective effects of oestrogen.
Diet adjustments: Replacing saturated fats with unsaturated fats, reducing salt intake(lowers blood pressure), and increasing dietary fiber helps lower blood cholesterol levels and reduces the rate of plaque buildup.
Contraction of atria: The muscles of the left and right atria contract simutaneously. This squeezes blood through the open atrioventricular valves into the ventricles. The semilunar valves remain shut.
Contraction of ventricles: The ventricles contract from the bottom up. This rise in pressure forces the atrioventricular valves shut to prevent backflow to the atria and also to create the first “lub” sound of the heartbeat. The pressure forces the semilunar valves open, shooting blood into the pulmonary artery and the aorta.
Heart relaxes: The heart muscles relax. To prevent the high-pressure blood in the arteries from slipping back down into the ventricles, the semilunar valves snap shut to create the second “dub” sound. Blood from the vena cava and pulmonary vein trickles back into the passive atria, and the cycle repeats.
Antibiotics are a distinct class of drugs used to treat infections.
They are used for the treatment of bacterial infecttions.
They work by **disrupting the cellular processes of bacteria (e.g. preventing them from building cell walls/reproducing), killing them or stopping their growth.
Bacteria are living cells with their own metabolic pathways and structures (such as cell walls).
Viruses are non-living particles that do not have their own cell walls, cell membranes, or independent transport systems. Instead, they hijack your body’s own cells to reproduce.
Antibiotics target bacterial structures specifically, rendering it useless against viral infections (e.g. common cold, flu, chickenpox).
Some bacteria possess genes that make them resistant to specific antibiotics. When an antibiotic is used, these resistant bacteria are not killed, which significantly reduces the effectiveness of the drug.
Random mutation. Within a population of bacteria, some individuals undergo random genetic mutations. A mutation may accidentally give a bacterium a gene that makes it resistant to a specific antibiotic.
Selection pressure. When a person takes an antibiotic, the drug acts as a selection pressure. It kills off all the normal, vulnerable bacteria.
Survival. The mutant, resistant bacteria survive the antibiotic treatment.
Reproduction. With their competitors wiped out, the surviving resistant bacteria have more resources. They multiply rapidly, passing on the gene for antibiotic resistance to their offspring.
Spread. Over time, the entire population becomes resistant, creating a strain of superbugs.
MRSA is an example of a dangerous bacterium that has developed resistance to many commonly used antibiotics. It is problematic in hospitals where open wounds and weakened immune systems are common.
No prescriptions for viral infections: Doctors shoulld never prescribe antibiotics for colds or sore throats caused by viruses.
Complete the full course: Patients must finish their entire prescribed course of antibiotics, even if they feel better. Stopping early leaves the most resillient bacteria alive to mutate and replicate.
Restrict agricultural use: Avoid using antibiotics as growth promoters in livestock farming, as this introduces low levels of drugs into the environment, accelerating resistance.
Hygeine controls: Maintaining strict hygeine in medical settings prevents the spread of existing resistant strains like MRSA.
Aerobic respiration is the series of chemical reactions occurring inside living cells that use oxygen to completely break down nutrient molecules (primarily glucose) to release energy for metabolic processes.
Since it completely oxidizes glucose, aerobic respiration releases a relatively large amount of energy compared to anaerobic respiration. Most of these reactions take place inside specialized cellular structures called mitochondria.
Lactic acid builds up in muscles and blood during vigorous exercise causing an oxygen debt.
High concentrations of lactic acid can cause muscle fatigue and cramps.
This lactic acid build up creates an oxygen debt. This is the extra volume of oxygen required by the body after exercise to completely break down the accumulated lactic acid.
Continuation of a fast heart rate: Your heart continues to beat quickly after exercise to rapidly transport lactic acid via the bloodstream away from your muscles and carry ti to the liver.
Continuation of deeper and faster breathing: You continue to breathe heavily to take in extra oxygen. This oxygen is absorbed into the blood and transported directly to the liver.
Aerobic respiration of lactic acid in the liver: Once inside the liver, the extra oxygen is used to aerobically respire the lactic acid, breaking it down safely into carbon dioxide and water.
Larynx: Located at the top of the trachea. Contains vocal cords used to produce sound.
Trachea: Main airway leading from throat to lungs.
Function of cartilage: Trachea is lined with C-shaped rings of cartilage. These rings keep the trachea open at all times, preventing it from collapsing inward whent eh pressure drops during inhalation.
Bronchi: Trachea splits into 2 tubes, the left and right bronchi, each leading into a lung.
Bronchioles: Smaller, highly branched tubes branching off the bronchi. Distributes air throughout all parts of the lungs.
Alveoli: Tiny air sacs at the end of the bronchioles where gas exchange actually takes place. Surrounded by a network of associated capillaries.
Diaphragm: A dome-shapped sheet of muscle separating the thorax (chest cavity) from the abdomen.
Large surface area: Millions of alveoli collectively create a massive surface area, allowing large amounts of gas to diffuse simultaneously.
Thin surface: The walls of both the alveoli and the capillaries are only one cell thick. This ensures a very short diffusion distance for oxygen and carbon dioxide.
Good blood suppply: A dense network of capillaries constantly moves blood past the alveoli. This brings carbon dioxide-rich blood to the lungs and carries oxygenated blood away, maintaing a steep concentration gradient.
Good ventilation with air: Breathing continuously replaces old, low-oxygen air with fresh, high-oxygen air, preserving the steep concentration gradient required for rapid diffusion.
To demonstrate that expired air contains significantly more carbon dioxide than inspired air, you can set up a simple boiling tube apparatus containing limewater.
Carbon dioxide turns clear limewater milky or cloudy.
Air is drawn through one flask when you inhale, and your exhaled breath is bubbled through a second flask when you exhale.
The result is that the limewater in the exhalation tube turns cloudy almost instantly, whereas the inhalation tube remains clear for a long time, proving that expired air has a much higher concentration of carbon dioxide.
Physical activity begins. Musccle cells increase their rate of aerobic respiration to produce more ATP for muscle contraction.
Carbon dioxide accumulates. As a waste product of this respiration, the carbon dioxide concentration in the blood increases.
Brain detects deoxygenated blood. The blood passes throught the brain, where specialized receptors detect this high carbon dioxide level.
Signal is sent to the diaphragm and intercostal muscles.
The response is an increase rate (more breaths per minute) and a greater depth (larger volume per breath of breathing.
The purpose of the rapid gas exchange accelerates the removal of toxic carbon dioxide from the blood and supplies the extra oxygen needed by the muscles.
The air we breathe contains dust, smoke particles, and pathogens. The respiratory tract uses a two-part defense mechanism to keep the lungs clean.
Goblet cells are specialized cells scattered along the lining of the trachea and bronchi. They synthesize and secrete sticky mucus.
Mucus traps dust, dirt, and pathogens before they can reach the alveoli.
Ciliated cells are cells that have tiny, hair-like extensions called cilia.
The cilia beat in a synchronized, wave-like motion, pushing the trapped mucus up and out of the airway toward the larynx/throat, where it can be safely swallowed or coughed out.
Respiration is the chemical reactions in cells that break down nutrient molecules and release energy for metabolism.
Unlike breathing, which is the mechanical movement of air into and out of the lungs, respiration is a microscopic process that occurs continuously inside every living cell.
Living organisms do NOTproduce energy. They RELEASE it from food and use it to drive metabolic processes. There are seven specific uses of energy.
Muscle contraction: To allow movement of the whole body, as well as internal movements (e.g. churning of stomach, heart beating).
Protein synthesis: To link amino acids together into long chains to create proteins (e.g. enzymes, hormones, antibodies).
Cell division: To power processes like mitosis and meiosis for growth and tissue repair.
Active transport: To move substances across cell membranes against their concentration gradient (e.g. root hair cells absorbing mineral ions, or small intestine absorbing glucose).
Reminder that active transport is the movement of ions or molecules across the cell membrane, against a concentration gradient, using energy from respiration.
Growth: To make new cells and build complex biological molecules.
Passage of nerve impulses: To pump ions across axon membranes, allowing electrical signals to travel through the nervous system.
Maintenance of a constant body temperature: Used by mammals and birds to release heat energy to keep their internal core temperature steady, even when the environment is cold.
Yeast is a single-celled fungus that respires to break down sugar. Because respiration is an enzyme-controlled reaction, it is highly sensitive to changes in temperature.
Mix a fixed volume of yeast suspension with a fixed volume of glucose solution in a test tube.
Place the test tube into a water bath set at a specific temperature.
Leave the tube for 5 mins. to allow the mixture to acclimatize(to adapt or adjust to a new environment) to the temperature.
Attach a delivery tube leading from the test tube into a gas syringe, or invert a measuring cylinder over water to collect gas. Alternatively, count the number of bubbles produced per minute.
Record the volume of carbon dioxide gas produced in a set time frame.
Repeat the entire process using water baths set at different temps.
At low temperatures (e.g. 10°C – 20°C), the rate of respiration is low. Kinetic energy is low, meaning enzymes and glucose molecules move slowly and rarely collide.
At optimum temperatures (~35°C – 40°C), the rate of respiration increases. Molecules gain more kinetic energy, leading to more frequent successful collisions between active sites and substrates.
Past optimum temperatures (e.g. above 45°C – 50°C), the rate of respiration drops to zero. The high temperature disrupts the bonds holding the respiratory enzymes together which alters the shape of their active sites. The enzymes are denatured, and the reaction stops.
Carbon dioxide, $CO_{2}$, is excreted through the lungs. Carbon dioxide is made in body tissues during respiration, and here, it diffuses out of the blood into the air in the alveoli, then exhaled out.
Urea, excess water and ions are excreted through the kidneys. Urea is carried to the kidneys in the plasma where it is filtered out and leaves the body dissolved in the form of urine. Urea is formed in the liver from excess amino acids.
Blood enters the kidney under high pressure. It reaches the glomerulus, a tightly coiled knot of capillaries.
Water, glucose, and urea are filtered out.
Large molecules like blood cells and plasma proteins are too big to pass through, so they remain in the blood.
Selective reabsorption
As the filtered fluid flows along the nephron tubule, the body reclaims the substances it still needs. The blood vessels wrapped around the nephron pull these substances back into the bloodstream.
All of the glucose is reabsorbed back into the blood for respiration.
Some of the ions are reabsorbed depending on body requirements.
Most of the water is reabsorbed to prevent dehydration.
Urine formation
Whatever is not reabsorbed passes to the end of the nephron and collects as urine. Urine flows into the ureter, then down to the bladder.
Urine contains: urea, excess water, and excess ions.
Excretion is important because metabolic wastes like urea are highly toxic. If urea builds up in the blood, it damages cells, disrupts cellular chemistry, and can lead to organ failure.
Amino acid metabolism in the liver:
Assimilation is when the food molecules that have been absorbed now become part of the cells or are used by the cells. The liver converts absorbed amino acids into useful plasma proteins, such as fibrinogen for blood clotting.
Deamination is the removal of the nitrogen-containing part of amino acids to form urea. This process takes place in the liver to safely break down excess amino acids that the body cannot store.
The mammalian nervous system consists of the CNS and PNS.
The central nervous system consists of the brain and spinal cord. It acts as the body’s primary center for processing info and directing body functions. It is connected to different parts that make up the peripheral nervous system.
The peripheral nervous system consists of the nerves outside the brain and spinal cord. The cranial nerves link the brain to all organs in the head and some in the thorax and abdomen. The spinal nerves leave the spinal cord in pairs through gaps in between the vertebrae.
The presynaptic neurone is the neurone that carries the impulse to the synapse. The postsynaptic neurone is the neurone that carries the impulse away from the synapse.
The synaptic bulbs are swellings at the axons of neurones.
The presynaptic membrane is the surface of the synaptic bulb. It is separated by the synaptic gap from the postsynaptic membrane of the cell body or axon of the next neurone.
The postsynaptic membrane has a large number of protein receptors for the neurotransmitter substance.
There are vesicles in the synaptic bulb that contain many mitochondria and neurotransmitter molecules.
When an impulse arrives at the synaptic bulb it causes vesicles containing the neurotransmitter to move towards the presynaptic membrane.
The vesicles fuse with the presynaptic membrane, releasing the neurotransmitter into the synaptic gap.
The neurotransmitter diffuses across the synaptic gap and attaches to specific receptor sites on the postsynaptic membrane. These receptor sites ahve a complementary shape to the neurotransmitter, but the binding is only temporary.
The binding of the neurotransmitter triggers an impulse in the postsynaptic neurone. Once this has happened the neurotransmitter is broken down by an enzyme in the synaptic gap.
The mitochondria provide energy to reform the transmitter.
Homeostasis relies on a mechanism called negative feedback.
The set point is the normal, ideal level for a condition in the body (e.g. a core body temp. of 37°C or a specific blood glucose level).
How it works: If a factor deviates from the set point, the body detects this change and triggers a response that reverses the change to bring it right back to the set point.
Type 1 diabetes is a condition where the pancreas fails to secrete enough insulin, leading to dangerously high blood glucose levels. It is managed and treated using a combination of methods:
Insulin injections/insulin pump therapy: Regular doses of insulin are injected directtly into the subcutaneous fat layer to artificially lower blood glucose levels.
Blood glucose monitoring: Testing blood drop samples throughout the day to calculate exactly how much insulin is required.
Controlled diet: Carefully managing and balancing carbohydrate intake to prevent massive blood sugar spikes.
The hypothalamus detects changes in the temp. of the blood and sends electrical impulses along nerves to trigger a corrective response *(like shivering or sweating)
Sweating: Sweat glands secrete sweat onto the skin surface. As the water in sweat evaporates, it absorbs and removes heat energy from the skin, cooling the body down.
Vasodilation: Arterioles supplying the skin surface capillaries widen (dilate). This allows more blood to flow close to the skin surface, meaning more heat energy is lost to the environment via radiation.
Shivering: Muscles contract and relax rapidly. This muscle activity requires a high rate of respiration, which releases heat energy to warm the blood.
Insulation:
The fatty tissue layer reduces heat loss from the core.
Hair erector muscles contract, pulling the hairs upright. This traps a layer of still, warm air next to the skin, acting as insulation. More effective in furry mammals than humans.
Vasoconstriction: Arterioles supplying the skin surface capillaries narrow (constrict). This restricts blood flow to the skin surface, redirecting it to vital core organs and minimizing heat loss via radiation.
Adrenaline is released by the adrenal glands during stressful, scary or exciting situations to prepare your body to either fight the danger or flee away from it.
Increased breathing rate. Delivers more oxygen to lungs so it can diffuse into the blood.
Increased heart rate. Pumps blood faster to deliver oxygen and glucose to muscles rapidly.
Increased pupil diameter. Allows more light into eyes to improve visuall claritty and awareness.
Increased blood glucose concentration. Adrenaline stimulates the liver to break down stored glycogen into glucose. This extra glucose is released into the blood to provide energy for increased cellular respiration in working muscles.
The pupil reflex is an involuntary, automatic contraction of the iris muscle causing the pupil to constrict in response to bright light, and dilate in dim light.
In bright light, eye receptors detect high light intensity and send signals via the optic nerve to the brain. The circular muscles contract and the radial muscles relax. The pupil constricts (becomes smaller).
IN dim light, eye receptors detect low light intensity and send signals to the brain. The circular muscles relax and the radial muscles contract. The pupil dilates (becomes larger).
These muscles never contract at the same time. This makes them antagonistic.
Plants don’t have a nervous system, so they rely on chemical growth responses to interact with their environment. These growth responses are called tropisms.
Gravitropism is a response in which parts of a plant grow towards or away from gravity.
Phototropism is a response in which parts of a plant grow towards or away from the direction of the light source.
First, grow two sets of seedlings on wet cotton wool in Petri dishes in the dark.
Second, cover the seedlings with a cardboard box with a slit in the side that allows the light to enter from only one direction so the seedlings are exposed to unilateral light.
Third, place the seedlings on a clinostat arranged in a vertical position. The clinostat rotates four times every hour, exposing each side of the seedlings to the light.
Fourth, after two days you can see that the seedlings exposed to unilateral light grew towards the light source.
In conclusion, they were positively phototrophic.
Gravitrophism experiment:
Place a seedling horizontally in a dark room. The shoot will grow upwards and the root will grow downwards.
To eliminate the effect of gravity as a control, a clinostat is used.
The result is that since there is more auxin on the shaded/lower side, the cells on that size elongate much faster than the cells on the lit/upper side. This unequal growth causes the shoot to bend toward the light or upward away from gravity.
Asexual reproduction is a process resulting in the production of genetically identical offspring from one parent.
Since they are genetically identical, there is little variation among offspring. Any variation is due to the effect of the environment (e.g. availability of nutrients and water determine growth of organism).
Binary fission is a form of asexual reproduction that is used by prokaryotes (e.g. bacteria) where a single cell divides into two identical daughter cells.
EXAMPLE:Bacteria are microscopic organisms made up of one cell. THey do not have a nucleus, but a loop of DNA. When bacteria reproduce asexually, the DNA loop is duplicated so that there is some for each new cell. The bacterial cell divides into two by making a new cell wall.
Fast. Organisms can reproduce rapidly to spread and colonize areas where the parent plants grow. Plants grow more rapidly from tubers than seeds. Also only requires one parent and it saves time instead of looking for a mate, which uses energy.
Lack of genetic variation. All offspring are genetically identical clones. If a change in their environment occurs, everyone is vulnerable.
Rapid colonization. Populations can increase very quickly in a favorable, stable environment, allowing the species to outcompete others.
Risk of extinction. If a new disease or change in climate occurs, the lack of variation means no individuals may have the resistance needed to survive, potentially wiping out the population.
Succession/traits given to offspring. Favorable traits are passed on 100% of the time, ensuring that if the parent is well-adapted to the niche, the offspring will be too.
Overcrowding. A rapidly increasing population may result in lots of competition for essential things such as food, water, and space.
Uniformity. Every plant will have the same characteristics, making it easier for farmers to manage and harvest crops mechanically.
Vulnerability to disease. If a specific pest or pathogen attacks one plant, then the whole field will be affected due to lack of variation and no genetic resistance.
Speed to market. Asexually reproduced plants typically reach maturity faster than seeds, making harvesting faster.
Lack of adaptation. The crops can’t adapt to long-term changes in the soil or climate over generations.
Certainty of quality. If a parent plant has a high yield or tastes pleasant, these characteristics will be passed on to offspring.
Storage issues. Some asexually reproduced structures (like tubers) do not store as easily or as long as seeds, which are naturally dormant and resistant to dessication (the removal of moisture).
Sexual reproduction is a process involving the fusion of the nuclei of two gametes to form a zygote and the production of offspring that are genetically different from each other.
In sexual reproduction, it requires two parents that have sex organs. The sex organs make gametes.
Male gametes:
In animals, the male gametes are sperm cells.
In flowering plants, the male gametes are nuclei inside pollen grains.
Female gametes:
In animals, the female gametes are egg cells.
In floweing plants, the female gametes are inside structures called ovules.
During sexual reproduction, the nuclei of the gametes fuse together at fertilization. The fertilized egg or zygote divides to form an embryo, which may grow into a new individual plant.
Fertilization is the fusion of nuclei of gametes.
The nuclei of gametes are haploid and the nucleus of a zygote is diploid.
A haploid nucleus contains two full sets of chromosomes.
A diploid nucleus contains only one set of unpaired chromosomes.
Genetic variation. Offspring are genetically different to each other. This is the raw material for natural selection.
Time and energy waste. Individuals must find and attract a mate. This involves energy-intensive processes like building a nest, developing bright plummage, or fighting rivals.
Adaptation to changes. If the environment changes (e.g. new predator, climate shift, or disease), variation ensures that some individuals may possess advantageous traits to survive and reproduce.
Risk of predatation or disease. The process of searching for a mate or the act of mating can make individuals vulnerable to predators or the transmission of parasites.
Removal of harmful mutations. Sexual reproduction can help remove the population of harmful genetic mutations over many generations through recombination.
Slower population growth. Because only females can bear offspring (in most species) and a mate is required, the population increases much more slowly than asexual populations.
The uterus lining (endometrium) changes to ensure that if an egg is fertilized, it has a blood-rich place to implant.
Days 1-5 is menstruation. If fertilization did not occur in the previous cycle, the thick uterus lining breaks down and is lost through the vagina, a period.
Days 6-14 is repair and thickening. Stimulated by oestrogen, the lining starts to thicken again and its blood vessels regrow to prepare for a possible embryo.
Days 15-28 is maintenance. Stimulated by progesterone, the lining is maintained at its full thickness. It becomes more filled with blood vessels to provide nutrients for an implanted embryo.
Changes in the ovaries:
The ovaries focus on the maturation and release of the female gamete (egg).
Days 1-13 is the follicular phase. Inside the ovary, a follicle, which is a sac containing an immature egg, begins to develop and mature. This is triggered by Follicle Stimulating Hormone (FSH).
Day 14 is ovulation. A surge in Luteinizing Hormone (LH) causes the mature follicle to burst, releasing the egg from the ovary into the oviduct.
Days 15-28 is the luteal phase. The empty follicle transforms into a structure called the yellow body.
If no pregnancy occurs, the yellow body degenerates, progesterone levels drop, and the cycle restarts with menstruation.
The production sites change as the follicle develops and then transforms after ovulation.
Oestrogen is produced by the ovaries, specifically by the maturing follicles. Its role is to stimulate the repair and thickening of the uterus during the first half of the cycle.
Progesterone is produced by the yellow body (left behind in the ovary after egg is released). Its role is to maintain the thickness and blood supply of the uterus during the second half of the cycle.
If an embryo implants, the body must prevent menstruation, which requires keeping progresterone and oestrogen levels high.
Early pregnancy, first trimester:
The yellow body continues to produce oestrogen and progesterone. It is “saved” from breaking down by hormones released by the developing embryo.
Late pregnancy, four months onward:
The placenta takes over the role of hormone production. The placenta secretes high levels of both oestrogen and progesterone for the remainder of the pregnancy.
FSH is produced in the pituitary gland and it is secreted at the start of the cycle. It stimulates the maturation of a follicle in the ovary and triggers the ovaries to start secreting oestrogen.
Oestrogen is produced in the ovaries (developing follicle). It stimulates the repair and thickening of the uterus lining. High levels of oestrogen inhibit the further release of FSH to prevent multiple eggs from maturing, while stimulating a surge in LH.
LH is produced in the pituitary gland. A sudden surge in LH around Day 14 triggers ovulation and also stimulates the remains of the follicle to develop into the yellow body.
Progesterone is produced in the ovaries (yellow body). It maintains the thickness and blood supply of the uterus lining. It also inhibits the release of both FSH and LH to ensure no new follicles develop during the second half of the cycle.
If fertilization and implantation occur, the hormonal balance shifts to protect the developing embryo.
Lining is maintained. Progesterone levels remain high instead of dropping, preventing the uterus lining from breaking down and also prevents mestruation and losing the embryo.
Uterus and mammary gland development. Oestrogen levels remain high.
Inhibition of FSH and LH. Since progesterone and oestrogen levels remain high, FSH and LH are suppressed to ensure no ovulation occurs during pregnancy.
Placenta handles hormones. The placenta takes over the production of progesterone and oestrogen from the yellow body to maintain the pregnancy until birth.
Testosterone is a hormone that stimulates changes in a boy’s body as he develops into an adult during puberty.
Scrotum: Pouch of skin containing the testes. Hangs outside body. Keeps testes cooled because sperm cells need less than 37°C.
Sperm duct: Connects tubules to urethra.
Urethra is a duct that brings urine out of the body from the bladder.
Prostate gland: Secretes fluid that mixes with sperm to form semen, which nourishes the sperm and helps them move.Sugars are used as an energy source for respiration.
Seminal vesicles: Glands that produce a nutrient-rich, sugary fluid that provides energy for the sperm to swim. This fluid is a major component of semen.
Penis: An organ that transfers semen into the female reproductive system during sexual intercourse.
The flagellum(tail) is a long, whip-like structure that extends the back of the sperm cell.
Provides movement for sperm cell.
By lashing back and forth, the flagellum propels through the cervix and uterus toward the oviduct, where fertilization occurs.
Sperm cells have a high concentration of mitochondria packed into the section between the head and the tail.
Mitochondria are the site of aerobic respiration.
Provides energy for the flagellum to beat. Without this energy source, the sperm would not be able to sustain the long journey to the egg.
The acrosome is a specialized vesicle (a small sac) located at the very front of the sperm’s head.
It contains digestive enzymes.
When the sperm contacts an egg, these enzymes are released to digest a pathway through the jelly coat of the egg cell. This allows the sperm nucleus to enter the egg and fuse with the nucleus.
Ovaries: Female sex organs that produce the female gametes (ova or eggs).
Oviducts: Narrow tubes that connect the ovaries to the uterus and contains cilia to push the egg along the oviduct. Also uses peristalsis. Site of fertilization.
Fertilization is the fusion of nuclei from a male gamete (sperm) and a female gamete (egg cell).
Uterus: Organ in the center of the pelvic cavity. Site of implantation of the embryo. Supports fetus by providing a thick, blood-rich lining (endometrium) and muscular walls that contract during birth.
Cervix: Ring of muscle at the lower end of the uterus. Holds developing fetus in place during pregnancy. Dilates during labor to allow baby to pass into the vagina.
Vagina: Muscular tube leading from cervix to outside of body. Site where sperm is deposited during sexual intercourse. Acts as birth canal during childbirth.
The egg cell contains a large volume of cytoplasm which acts as an energy store.
Rich in nutrients. Contains the yolk.
Provides necessary energy and raw materials for the early development of the embryo. After fertilization, the zygote must divide many times as it travels down the oviduct toward the uterus; the energy store sustains it until it can implant in the uterus lining and begin receiving nutrients from the mother.
The egg is surrounded by a specialized outer layer known as the jelly coat. This layer has two critical roles during fertilization:
First, selection. It contains receptor sites that ensures only sperm from the same species can bind to and penetrate the egg.
Second, the fertilization membrane. Immediately after the first sperm nucleus enters the egg, the jelly coat undergoes a chemical change that makes it harden or become impenetrable.
The function of the jelly coat prevents more than one sperm cell penetrating the egg. If multiple sperm fertilized one egg, there would be too many sets of chromosomes and would not survive.
Umbilical cord: Tube-like structure connecting fetus to placenta. Contains blood vessels that contains blood vessels that transport substances between placenta and fetus.
The umbilical vein carries oxygenated blood and nutrients (e.g. glucose/amino acids, oxygen, mineral ions/vitamins, and water)to baby.
The umbilical artery carries deoxygenated blood and waste products (e.g. $CO_{2}$, urea, water)away from baby.
Placenta: Disc-shaped organ embedded in the wall of uterus, connected to fetus by umbilical cord. Exchanges materials, removes waste, barrier from pathogens, and produces hormone (progesterone, maintain lining of uterus during pregnancy).
Some pathogens and toxins can pass across the placenta and affect the fetus.
Amniotic sac: Tough, thin, transparent membrane that encloses the fetus and amniotic fluid. Contains amniotic fluid and prevents infections from reaching the fetus from the vagina.
Amniotic fluid: Liquid that fills the amniotic sac, surrounds the developing fetus. Acts as a shock absorber, preventing the fetus from physical impact or injury. Maintains constant temperature. Allows fetus to move freely for bone and muscle development.
Pollination is the transfer of pollen grains from an anther to a stigma.
Self-pollination is the transfer of pollen grains from the anther of a flower to the stigma of the same flower or a different flower on the same plant.
Cross-pollination is the transfer of pollen grains from the anther of a flower to the stigma of a flower on a different plant of the same species.
Since self-pollination is the transfer of pollen grains of the same flower, this leads to very low genetic variation in the offspring since they are very similar to the parent.
Since cross-pollination is the transfer of pollen grains to a flower on a different plant of the same species, this leads to high genetic variation in the offspring because it combines two different genetic material from two individuals.
Capacity to respond to environmental change:
Self-pollinated flowers result in not being able to adapt easily to changes in the environment due to the lack of genetic variation .
Cross-pollinated flowers provides the “raw material” for natural selection. If there is an afvantageous trait in a plant that allows them to survive or adapt to a change in the environment, this trait can be passed on to offspring.
Reliance on pollinators:
For self-pollinated flowers, there is little to no reliance on external pollinators (e.g. bees, wind), which is an advantage in habitats where pollinators are scarce or where plants are wildly scattered. This ensures there is still seed production even in isolation.
For cross-pollinated flowers, there is a high reliance on pollinators or wind. If the specific pollinator for a species declines (e.g. caused by habitat loss or pesticides), the plant population may fail to reproduce, leading to a decline in numbers.
Inert means chemically inactive. This example uses a solution of copper(II) sulfate, which has blue copper ions, sulfate ions, and hydrogen and hydroxide ions.
Using carbon/graphite electrodes (inert)
At the cathode: Copper ions are discharged. The copper coats the electrode.
$$2Cu^{2+}(aq) + 4e^{-} \rightarrow 2Cu (s)$$
At the anode: Oxygen bubbles off. $$4OH^{-}(aq) \rightarrow 2H_{2}O(l) + O_{2}(g) + 4e^{-}$$
So copper and oxygen are produced. The blue color of the solution fades because the concentration of copper ions in it decreases as the ions are discharged.
Using copper electrodes (not inert)
At the cathode: Copper is formed and coats the electrode. $$Cu^{2+}(aq) + 2e^{-} \rightarrow Cu(s)$$
At the anode: The anode dissolves, giving copper ions in solution. $$Cu(s) \rightarrow Cu^{2+}(aq) + 2e^{-}$$
As the anode dissolves, the copper ions move to the cathode to form copper. So, copper moves from the anode to the cathode. The solution stays blue because the concentration of copper stays the same.
The more reactive an element is, the longer it stays as an ion. Therefore, if a metal is more reactive than hydrogen, its ions stays in solution and hydrogen bubbles off.
If a metal is less reactive than hydrogen, the metal forms.
At the anode, a NON-METAL OTHER THAN HYDROGEN forms.
If it is a concentrated solution of a halide(a compound containing Cl-, Br-, or I- ions), then chlorine, bromine, or iodine form.
If the halide solution is dilute, or there is no halide, oxygen forms.
The reactants and products have energy. It is stored as chemical energy in their bonds. The total energy does not change, during a reaction. It is the same on each side of the arrow. The products must have less energy than the reactants do.
In an exothermic reaction, the products have less energy than the reactants do. Energy has been given out.
The total energy does not change, during the reaction. It is the sam eon each side of the arrow. So it follows that the products must have more energy than the reactants do.
In an endothermic reaction, the products have more energy than the reactants do. Energy has been taken in.
Only chemical produced is water, which is harmless
Hydrogen can be made by the electrolysis of water, which is plentiful, on adding a little acid.
Disadvantages:
Hydrogen is a gas. To reduce its volume and make it practical to use, it must be stored as a liquid under high pressure. This can be expensive or hard to maintain.
Hydrogen filling stations are not yet widely available.
Most hydrogen is obtained by fossil fuels, and where it is obtained by electrolysis, the electricity is mostly from power stations that burn fossil fuels. These are linked to pollution and climate change.
A reaction goes faster when the concentration of a reactant is increased. Reduce the concentration to slow down the reaction.
EXPLANATION: There are more particles per unit volume, ∴ higher frequency of collisions ∴ higher frequency of SUCCESSFUL collisions.
Changing the pressure of gases
A reaction involving gases goes faster when the pressure is increased. Decrease the presure to slow down the reaction.
EXPLANATION: Increasing gas pressure means more gas particles per unit volume, ∴ successful collisions are more frequent.
Changing the surface area of solids
A reaction goes faster when the surface area of a solid reactant is increased. Decrease the surface area of a solid reactant to slow down the reaction.
EXPLANATION: More particles of the solid are exposed, ∴ successful collisions are more frequent.
Changing the temperature
A reaction goes faster when the temperature is raised. A rate generally doubles for an increase of 10°C. Decrease the temperature to slow down a reaction.
EXPLANATTION: There are two reasons: there are more collisions, and more have sufficient energy to be successful.
Adding or removing a catalyst, including enzymes
A catalyst is a substance that increases the rate of a reaction, and is unchanged at the end of the reaction.
Enzymes are proteins made by cells, to act as biological catalysts.
Adding a catalyst increases the rate of a reaction.
EXPLANATION: A catalyst lowers the activation energy of a reaction, now the particles need less energy to react, ∴ more successful collisions and the reaction is faster.
For a chemical reaction to occur, reacting particles must collide with one another. Not every collision results in a reaction. A successful collision must meet these conditions:
The particles must collide with sufficient energy. This is the activation energy.
The particles must collide with the correct orientation.
When a reversible reaction is in equilibrium and you make a change, the system acts to oppose the change, and restore equilibrium. A new equilibrium mixture forms.
cracking hydrocarbons from petroleum.
The two gases are mixed and scrubbed to remove impurities.
The mixture is compressed. More gas is pumped in until pressure reaches 200 atm.
The compressed gas flows into the converter, a round tank with beds of iron at 450°C, where the key reaction occurs. Iron is the catalyst.
The mixture is cooled until the ammonia condenses to a liquid. The nitrogen and hydrogen are recycled to the converter for another chance to react. Steps 3 and 4 are continually repeated.
The ammonia is run into tanks and stored as a liquid under pressure.
The typical conditions in the Haber process:
450°C to give a faster rate
200 atm / 20,000 kPa is safer and saves money
an iron catalyst to speed up the reaction but does not affect yield.
Bases are oxides amd hydroxides of metals. They neutralize acids.
Examples: $CuO$ (copper oxide) and $NaOH$ (sodium hydroxide)
Alkalis are soluble bases. They can dissolve in water to release hydroxide ions.
Salts are ionic compounds formed when the hydrogen ions, $H^+$ in an acid are completely or partially replaced by a metal ion or an ammonium ion, $NH_4^+$.
Universal indicator changes color gradually depending on the concentration of H+ ions in a solution:
pH 0 to 6 (acidic): A high H+ conc. corresponds to lower pH numbers. For universal indicators, acidic solutions turn deep red/orange, meanwhile weak acids turn yellow/light green.
pH 7 (neutral): Equal conc. of H+ and OH- ions. Universal indicator turns green.
pH 8 to 14 (alkaline): Higher OH- conc. corresponds to higher pH numbers. Turns blue/deep purple.
The equation for the neutralization reaction between an acid and an alkali to produce water:
$$\text{H}^+\text{(aq)} + \text{OH}^-\text{(aq)} \rightarrow \text{H}_2\text{O(l)}$$
A want is a good or service which people would like to have, but which is not essential for living. People’s wants are unlimited.
The economic problem is that there are unlimited wants but limited resources to produce the goods and services to satisfy those wants. This creates scarcity.
The factors of production are those resources needed to produce goods or services. There are four factors of production and they are in limited supply.
To produce any good or service, a business must utilize four scarch resources. If any of these factors are missing, production cannot happen.
The four factors are:
land: all natural resources provided by nature (e.g. fields, forests, oil, metals)
labor: number of people available to make products, involves the human effort, skills, and mental or physical work put into production process
capital: finance, machinery and equipment needed for the manufacture of goods
enterprise: the skill and risk-taking ability of the person who brings the other resources or factors of production together to produce a good/service.
Increase the selling price while keeping cost of materials the same. This can be to establish a higher quality image for its product or service. Consumers might be convinced to buy it at a high price as a novelty factor.
Other costs might increase when trying to create this quality image.
Reduce the cost of materials but keep the price the same. The firm could use cheaper wood, bricks, etc. A higher value would be added if this method is used.
Lower priced materials might lower the quality of the product.
Unlimited liability is a legal situation where the owners are fully responsible for all debts of the business. Because the owner and the business are legally seen as the same entity, the owner may be forced to sell their personal assets to pay back creditors if the business goes bankrupt.
Limited liability is a legal protection for shareholders where their responsibility for business debts is restricted to the amount they invested in buying shares. If the business fails, their personal possessions are completely safe and cannot be used to pay off debts.
Private limited companies are businesses owned by shareholders but they cannot sell shares to the public.
Advantages:
Limited liability for shareholders.
Separate legal identity.
Easier to raise capital by selling private shares.
Disadvantages:
Complex and expensive legal setup.
Cannot sell shares to the public.
Financial accounts are partially viewable by competitors.
Public limited companies are businesses owned by shareholders but they can sell shares to the public and their shares are tradeable on the Stock Exchange.
Advantages:
Can raise massive amounts of capital quickly.
High public profile and status.
Exploits economies of scales easily.
Disadvantages:
Extreme risk of takeover by outsiders buying shares.
Full public disclosure of accounts is required.
Divorce of ownership and control(shareholders vs directors).
The most common objectives for businesses in the private sector are to achieve:
business survival
Focuses on keeping cash flowing and covering basic costs to avoid going out of business.
profit
Total income of a business (revenue) less total costs.
Private sector businesses aim to maximize or reach a target profit level to reqard owners and reinvest in the business.
Profits are needed to pay a return to the business owners for the capital invested and the risk taken and to provide finance for further investment in the business.
returns to shareholders
A shareholder is any individual, group, or institution that owns at least one share of a company’s stock. They are the legal owners of a limited company.
It is increased by increasing profit and increasing share price.
growth of the business
Expanding the business by opening new branches, increasing output, or hiring more staff.
Growth allows a business to benefit from economies of scale(lower average costs) and reduce risk of being taken over by competitors.
market share
% of total market sales held by one brand or business.
service to community
A social enterprise has social objectives as well as an aim to make a profit to reinvest back into the business.
Direction. They give managers and employees a clear target which reduces confusion about what the business is trying to achieve.
Motivation. Clear, achievable goals give employees something to work toward, increasing productivity.
Measurement. They act as a benchmark. At the end of the year, a business can compare its actual performance against its initial objectives to see if it succeeded.
Decision-making. They help prioritize resources. If the objective is growth, managers will approve budgets for expansion rather than saving cash.
Profits against wages: Owners want to maximize profits and dividends. Employyes want higher wages. This increases the business’s costs and lowers overall profit.
Growth against environment: Managers want to expand to achieve growth and boost status. The local community will object due to increased traffic, noise, air pollution, or destruction of natural spaces.
Price against profit quality: Customers want the highest quality goods at the lowest possible prices. Owners want to keep production costs low and selling prices high to maintain healthy profit margins.
Organizing training for entrepreneurs that gives advice, and support sessions offered by experienced business people
Premises
Enterprise zones, which provide low-cost premises
Finance
Loans for small businesses at low interest rates and grants if businesses start up in depressed areas of high unemployment
Labor
Grants to small businesses to train employees and help increase productivity
Research
Encouraging universities to make their research facilities available to new business entrepreneurs
A loan is a sum of money borrowed from a bank or govt. that must be paid back over an agreed period of time, usually with an extra cost called interest.
A grant is a sum of money given to a business by a govt. or supporting organization that does NOT have to be paid back, provided the business uses it for the agreed purpose (such as setting up in a high-unemployment area).
Number of employees: Some firms use production methods which employ very few people but produce high output levels. This is commmon for highly automated factories.
Value of output: A high level of output does not mean that a business is large when using the other methods of measurement.
Example: A firm employing few people might produce several highly expensive computers each year. This might give higher output figures than a firm selling cheaper products but more workers.
Capital employed: Similar limitation to the number of employees. A company employing many workers may use labor-intensive methods of production, giving low output levels and use little capital equipment.
More status and prestige for the owners and managers. Higher salaries are often paid to managers who control bigger businesses.
Lower average costs.
Larger share of its market. The proportion of total market sales it makes is greater, giving the business more influence when dealing with suppliers and distributors, and consumers are often attracted to the ‘big names’ in an industry.
Internal growth occurs when a business expands its existing operations. Examples include creating brand-new products, and setting up websites to target new global markets.
By external growth:
External growth is when a business takes over or merges with another business. This is through a merger or a takeover.
A merger is when the owners of two businesses agree to join their business together to make one business.
Horizontal integration is when one business merges with or takes over another on ein the same industry at the same stage of production.
Vertical integration is when one business merges with or takes over another one in the sam eindustry but at a different stage of production. Can be forward or backward.
Forward is merging with a business at a later stage of production.
Backward is merging with a business at an earlier stage of production.
Advantages: Reduces no. of competitors, opportunities for economies of scale, bigger share of the total market
Disadvantages: High risk of management and staff culture clashes.
Forward vert. integration:
Advantages: Guaranteed outlet for its product, profit margin made by retailer is absorbed by expanded business, info about consumer needs and preferences are obtained by manufacturer.
Disadvantages: Might lack operational experience running a retail sector shop.
Backward vert. integration:
Advantages: Guaranteed supply of important components, profit margin of supplier is absorbed by expanded business, supplier prevented from supplying other manufacturers, costs of components and supplies are controlled.
Disadvantages: Managing raw material extraction requires totally different skills than final production.
Examples of industries where small businesses are common are hairdressing, window cleaning, convenience stores, car repairs, plumbers. Businesses in these industries offer personal services or specialized products.
If they grew too large, it would be challenging to offer the close and personal service demanded by customers.
If the total number of customers is small, the businesses are most likely going to remain small. This also applies to businesses that produce goods or services of a specialized kind because this only appeals to a limited number of consumers.
The business can remain small depending on the owners’ preferences. The owner might keep their business small because they have a close relationship with staff, or it is easier to manage and avoids stress.
Recruitment is the process from identifying that the business needs to employ someone up to the point at which applications have arrived at the business.
Internal recruitment is when a vacancy is filled by someone who is an existing employee of the business.
External recruitment is whena vacancy is filled by someone who is not an existing employee and will be new to the business.
Employee selection is the process of evaluating candidates for a specific job and selecting an individual for employment based on the needs of the organization.
Unfair dismissal is when an employer ends a worker’s contract of employment for a reason that is not covered by the contract.
Discrimination at work is when the employer makes decisions that are based on ‘unfair’ reasons (e.g. skin color/race, different religion, opposite sex, age, disabled).
Health and safety is required for businesses. Businesses should provide clean water, proper ventilation, safety gear, and adequate training.
Legal minimum wage is the lowest hourly rate an employer can legally pay a worker.
the business is that it increases productivity, reduces mistakes, improves customer service and makes the business more adaptable to technology changes.
the employee is that it boosts job satisfaction, increases safety, reduces stress, and opens up promotion opportunities.
High productivity(output per worker) in a business usually comes from a highly motivated workforce that wants to work effectively, which results in profits. The main benefits are:
high output per worker, keeping costs low and increase profits
willingness to accept change
two-way communication with management
low labor turnover/a loyal workforce, reducing the cost of recruiting workers who leave
low rates of abstenteeism, reducing the disruption caused by absence from work
low rates of strike action, avoiding damage to customer relations.
F.W. Taylor’s assumption is that workers were purely motivated by money or personal gain. Therefore, if workers were paid more, they will work more effectively.
Taylor broke down factory workers’ jobs into simple processes and then calculated how much output they should be able to do in a day. If they produced this target output, they would be paid more money.
Taylor saw employees rather like machines. When they were working hard, their productivity would be high, therefore labor costs would be low for each unit produced.
THE ISSUE: Completely ignores the emotional and social sides of working. Makes jobs monotonous. Can cause high staff turnover and strikes in the long run.
According to Herzberg, humans have two sets of needs:
one is for the basic needs (the ‘hygiene’ factors)
second is for a human being to be able to grow psychologically (the ‘motivatiors’).
The ‘hygiene’ factors are things surrounding the job. This prevent dissatisfaction, but do NOT motivate. If these basic needs are not meant, workers will be deeply dissatisfied. Note that improving these will NOT make workers work harder, it stops them from complaining.
The ‘motivators’ relate to the actual content of work itself. These factors help increase their productivity.
A salary is payment for work, usually paid monthly.
Salaries are a fixed cost for the business. It is calculated as an annual amount, split into 12 equal monthly payments, no matter how many hours are worked.
Laissez-faire leadership makes the broad objectives of the business known to employees, but then they are left to make their own decisions and organize their own work.
Best for: Research labs or creative design studios with highly independent, self-motivated experts.
Drawback: Can lead to a complete lack of direction or coordination if the team lacks discipline.
Downsizing is the deliberate process of reducing the total number of employees a business employs to cut operating costs and improve structural efficiency.
Downsizing happens due to:
Automation: Replacing human labor with mechanical machinery or computerized automation systems to boost output speeds and cut long-term operational costs.
Reduced demand: Falling sales due to economic recession or shifting consumer tastes mean fewer workers are needed to handle output.
Need to lower costs: Facing fierce competitor prices forces a firm to cut its wage bill to protect profit margins.
A marketing strategy is a plan to combine the right combination of the four elements of the marketing mix for a product or service to achieve a particular marketing objective(s).
The product must align with a premium quality and unique selling points.
The business should consider what type of product the target market likes, if the product is innovative or existing, and if the product needs to be changed to meet consumer wants.
The price must be reasonable and can establish a high price to reflect high quality, therefore consumers are willing to purchase it as a novelty factor.
The business should also take competitors prices into consideration, and decide what pricing strategy to use (e.g. competitive, penetration).
The business must consider how the target market should buy its products, and where should it be sold, what channels of distribution should be used, and what channels of distributions competitors use.
The business must consider what method they should use to promote the product to attract the target market, what methods competitors use, and check the budget available to promote the product.
After deciding on the product, price and promoting the product, the business has to actually sell the product to the consumer. The business must ensure that the product or service must be available where and when the customers want to buy it. Businesses should consider how and where consumers can buy the product and how will it affect how well it will sell.
The wholesaler performs the function of breaking bulk, where wholesalers buy products from manufacturers in large quantities and then divide up the inventory into much smaller quantities for retailers to buy.
Advantages:
Wholesaler saves storage space for small retailer and reduces storage costs.
Small retailers can purchase fresh products in small quantities from wholesaler because they have a relatively short shelf life before they deteriorate.
Wholesaler may give credit to retail customers so they can take the goods straightaway and pay at a later date.
Wholesaler can give advice to small retailers about what is selling well. They can also tell the manufacturer what is selling well.
Disadvantages:
May be more expensive for the small shop to buy from a wholesaler than if it bought straight from the manufacturer.
Wholesaler may not have full range of products to sell.
Takes longer for fresh produce to reach the shops, so may not be as good quality.
Wholesaler may be a long way from the small retailers.
The consumer price is often higher than direct selling as both the wholesaler and retailer have to cover costs and make a profit.
Without a wholesaler, a manufacturer has to process many orders from retailers.
With a wholesaler, a manufacturer has less paperwork.
When deciding a price for either an existing product or a new product, the business must be very careful to choose a price which will fit in twith the rest of the marketing mix for the product. Business must be careful when considering a pricing strategy for the specific type of product being sold to consumers.
DEFINITION: The cost of manufacturing the product plus a profit mark-up. It involves estimating how many units of the product will be produced, calculating the total cost of producing this output, and adding a percentage mark-up for profit.
Benefits:
Easy to apply the method.
Different profit mark-ups could be used in different markets.
Each product earns a profit for the business.
Limitations:
If the selling price is higher than competitors’ prices, businesses can lose sales.
A total profit will only be made if sufficient units of the product are sold.
No incentive to reduce costs. Any increase in costs is just passed on to the customer as a higher price.
DEFINITION: When the product is priced in line with or just below competitors’ prices to try to capture more of the market.
Benefits:
Sales are likely to be high since the price is at a realistic level and the product is not under- or over-priced.
Avoids price competition, reducing profits for all businesses in the industry.
Used when it is difficult for consumers to distinguish between products of different businesses.
Limitations:
If *costs of production for a business are higher than those of competitors (maybe due to higher quality), then a competitive price could lead to losses being made.
A higher quality product might need to be sold at a price above competitiors’ prices to give it a higher quality image.
Detailed research would be needed into what prices competitors are charging, and this research costs time and money.
DEFINITION: Where a high price is set for a new product on the market. This is mainly used for a product that is a new invention, or a new development of an old product, ∴ it can be sold on the market at a high price and people are willing to purchase this at a high price because of the novelty factor.
Benefits:
Can help establish the product as being of good quality.
High research and development costs can be rapidly regained from the profit made on the product at the high price.
If the product is unique, a high price will lead to profits being made before competitors launch similar products ∴ the price has to be reduced.
Limitations:
High price can discourage some potential customers from buying it.
High price and high profitability may encourage more competitors to enter the market.
Price elastic demand is where consumers are very sensitive to changes in price. For example, if the price of a chocolate bar rose by 5%, they might find alternative chocolate bars and sales might fall by 15%. The percentage change in quantity demanded is greater than the percentage change in price.
Price inelastic demand is where consumers are not sensitive to changes in price. For example, if electricity prices rose by 15%, it would not cause much of a fall in sales (perhaps 5%) as most consumers will carry on buying the product at the higher price. The percentage change in quantity demanded is less than the percentage change in price.
A very high price for a high quality product may mean that high-income customers wish to purchase it as a status symbol.
If a price is set just below a whole number (e.g. 99 cents instead of 1 dollar) creates the impression of a very cheap product.
Supermarkets may charge low prices for products purchased on a regular basis, which will give customers the impression of being given good value for money.
Repeat sales are often made when the price reinforces consumers’ perceptions of the product. This may be its brand image when the price is set high.
Many businesses sell their products using different pricing methods for different segments of the market or at different times. This is often called dynamic pricing.
Dynamic pricing is when businesses change product prices, usually when selling online, depending on the level of demand.
The marketing mix is a term which is used to describe all the activities which go into marketing a product or service. These activities are summarized as the four P’s:
Product, applying to the good or service itself (design, features, quality). Business have to consider how the product compares to other competitors’ products, the packaging to help identify it, and if it’s a service, the service should be better than the rivals’ services.
Price, the cost at which the product is sold to the customer. A comparison must be made with the prices of competitors’ products. This should cover costs.
Place, the channels of distribution that are selected. Business should consider how the product will get into the market and to the customer that wants to use the product. The manufacturer should also consider if the product is sold to shops that sell to the public or to wholesalers or to customers directly.
Promotion, how the product is advertised. The advertising media is considered when promoting. It includes discounts that may be offered or any other types of sales promotion (e.g. money-off vouchers or free gifts)
(Remember these, as they are important to understand the activities mentioned in the marketing mix.)
A brand name is the unique name of a product that distinguishes it from other brands.
Advertising and other promotions will constantly refer to this brand name and will make consumers aware of the qualities of the product to try to persuade them to buy it.
Brand loyalty is when consumers keep buying the same brand again and again instead of choosing a competitor’s brand.
Brand image is an image or identity given to a product which gives it a personality of its own and distinguishes it from its competitors’ brands.
Packaging is the physical container or wrapping for a product. It is also used for promotion and selling appeal.
These are the main considerations of packaging:
It must be suitable for the product.
It should protect the product.
It should not allow the product to spoil.
It has to allow the product to be used easily.
It has to be suitable for transporting the product from the factory to the shops (should not be too delicate or else the product could easily get damaged).
The packaging has to appeal to the consumer, therefore the color and shape of the container is very important.
The labels on some products must, as a legal requirement, carry important information about the product (e.g. how to store it, expiry dates, ingredients that it contains).
The product life cycle describes the stages a product will pass through from its introduction, through its growth until it is mature, and then finally its decline.
Development
Product is developed.
Testing prototype.
Market research is carried out before product is launced on to market.
No sales.
Introduction
Slow sales growth initially because consumers don’t know product is on market.
Informative advertising is used until product is known.
Price skimming may be used if product is a new development and there are no competitors.
No profits made because no development costs are covered yet.
Growth
Advertising transitions to persuasive advertising to encourage brand loyalty.
Slightly reduced prices as new competitors enter market to take some customers.
Profits are made as development costs are covered.
Maturity
Sales now slowly increase.
Intense competition.
Pricing strategies are now competitive or promotional pricing.
Lots of ads to maintain sales growth.
Profits are at their highest.
Saturation
Sales are now stabilized at their highest point.
High competition but no new competitors.
Profits start to fall as sales are static.
Prices have to be reduced to stay competitive.
Decline
Sales decline as new products come along or because product loses appeal.
Product is usually withdrawn from market when sales become so low and prices have been reduced so far that it becomes unprofitable to produce product.
A branded product is likely to be sold at a high price when it is first introduced to the market. A low price could give the wrong message about quality.
Prices are likely to be relatively higher than those of competitors in the growth stage as the product may still be newer than those of rivals.
In the saturation or maturity stage, when the business will want to try to stop sales declining, the price is likely to be reduced as competitors may have launched newer versions of their own products.
Some substantial price discounts might be offered during the decline stage, especially if the business does not plan to extend its life.
Promotion
Spending on production is higher than the introduction because the business needs to inform consumers of the product. A clear identity needs to be established if the product is a completely new brand.
Advertising will be used less when the product has become well known or if the business wants to spend budget on marketing for other products.
Promotion spending might be increased again if the business decides to implement an extension strategy.
An extension strategy is a way of keeping a product at the maturity stage of the life cycle and extending the cycle.
The business will have to decide the purpose of the advertising.
Is it to capture a new market?
is it to increase market share?
Is it to improve the image of the company?
Is it to create or improve a brand image?
Decide the advertising budget.
The business will need to decide how much to spend on advertising. Too much = money wasted, too little = less effective advertising.
For cost-effectiveness, the business can predict how much sales will be in the future and then spend a percentage of the predicted sales on advertising the product.
Using this method, the expense of advertising is related to the revenue brought in by the sales of the product.
Sometimes the budget will be set by how much competitiors spend on advertising.
The budget is also decided by how much the business can afford to spend, true for small businesses.
Create an advertising campaign.
The business will need to decide what sort of advertising campaign to run. For example, will the ads need to attract young people?
The target audience refers to people who are potential buyers of a product or service. The target audience and the purpose of the advertising are considered when making a campaign.
Select the media to use.
The business will need to decide which is the best type of advertising media to use. The target audience determines the suitable form of media. They need to ensure it reaches the target audience.
For cost-effectiveness, it is better to choose a cheaper, suitable medium if the target audience isn’t a part of the mass market. It would be pointless to use a popular medium such as television if your target audience is a part of a niche market.
Evaluate the effectiveness of the campaign.
The business needs to see if sales have increased as a result of the advertising campaign or see if the product’s brand image has improved. For example, has the campaign met its objective?
Social media marketing is a form of internet marketing that involves creating and sharing content on social media networks in order to achieve marketing and branding goals.
It includes activities such as posting text and image updates, videos, and other content that achieves audience engagement, as well as paid social media advertising.
Viral marketing is when consumers are encouraged to share information online about the products of a business.
e-commerce is the ‘online’ buying and selling of goods and services using computer systems linked to the internet and apps on mobile phones.
Websites can be used to promote the company and its products worldwide much more cheaply than other forms of marketing (e.g. setting up shops in many countries).
Orders can be taken via the internet and sent directly to the warehouse for dispatch.
Consumers might be encouraged to purchase more products than intended by attractive and easy-to-follow websites (e.g. links to other products that could be bought with the original purchase).
Can easily make online purchases of supplies and materials from other businesses, called business-to-business (B2B) e-commerce.
Selling onlinme makes dynamic pricing much easier for businesses.
Since many businesses are now offering e-commerce websites, the competition is very high. If a business charges higher prices than competitiors, consumers can easily find an alternative.
Website design must be very clear, attractive, and easy to handle. Website designs can be expensive, and frequent updates add more costs.
Transport costs per product sold are likely to be higher than selling through traditional shops. The business has to consider whether the consumer has to pay for these costs, or if that becomes uncompetitive for the business.
No face-to-face contact, which does not give the business useful market research feedback.
Consumers in most countries have the legal right to reject goods brought through e-commerce because they have not seen, touched, or worn the actual good. Returns can add to business costs.
A large warehouse + efficient inventory control system is essential to fulfil consumers’ orders accurately and efficiently despite not needing to establish shops in many countries.
e-commerce is not suitable for businesses that sell personal services because this may require face-to-face service for consumers
No need to leave the house to go shopping, allowing for convenience.
Comparisons between prices and products or services offered can be easily made by going from one website to another, or using price comparison websites.
Payment by credit or debit card is easy.
Consumers can now easily access products and services from businesses located abroad. This would be expensive without e-commerce.
Consumers can buy some products for prices much lower than they would be without the competition of e-commerce.
Customers can buy parts or components from manufacturers without the addition of retailers’ profit margin.
Packaging and transport costs have fallen due to competition on the internet, making it cheaper to buy from abroad now.
Consumers need access to the internet to see and purchase products or services.
Computer systems failures or weak internet connections can result in frustrated consumers who are unable to access websites or make their purchases.
Products can’t be seen, touched or tried on and returning products because they are unsuitable is often inconvenient.
No face-to-face contact with sales staff so it can be difficult to find out more info about the good or service being sold other than that which is provided on the website.
Note that in the book it is quite old. It is now possible to email, call, or make meetings with these sales staff.
Many consumers are concerned about identity theft or fraudulent use of credit cards if they buy goods online.
*Again, the book is quite old. Security systems have significantly improved.
