Biology Paper 1 Exam Questions

• This model exam question booklet is split into three parts to aid in your science studies.
• Part 1 provides short response questions, aiming to help create flashcards and self-quizzes for regular review.
• Part 2 features extended response questions (4-6 marks), targeting areas less recently assessed or frequently examined, to encourage preparation and practice.
• Part 3 focuses on required practical sections, offering step-by-step guidance, short response questions, and extended response questions (4-6 marks) for practical skills.

Biology Paper 1 Topics

• Cell Structure and Transport (B1)
• Cell Division (B2)
• Organisation and the Digestive System (B3)
• Organising Animals and Plants (B4)
• Communicable Disease (B5)
• Preventing and Treating Disease (B6)
• Non-Communicable Disease (B7)
• Photosynthesis (B8)
• Respiration (B9)
• Light Microscope (RP1)
• Bacterial Growth (RP2)
• Osmosis (RP3)
• Qualitative Reagents (RP4)
• Enzymes (RP5)
• Light Intensity (RP6)

B1: Cell Structure

• A eukaryotic cell has a cell membrane, cytoplasm, and genetic material enclosed in a nucleus.
• A prokaryotic cell lacks a nucleus; its DNA is a loop, possibly with plasmids.
• A plasmid is a small ring of DNA.
• Bacteria are prokaryotic cells.
• Prokaryotic cells are much smaller than eukaryotic cells.
• The nucleus controls the cell.
• The cytoplasm is the site of chemical reactions.
• The cell membrane controls what enters and leaves the cell.
• Mitochondria are the site of respiration.
• Ribosomes are the site of protein synthesis.
• Chloroplasts are the site of photosynthesis.
• Permanent vacuoles support the cell and contain cell sap.
• The cell wall is strengthened by cellulose.
• Common parts of an animal cell include the nucleus, cell membrane, cytoplasm, mitochondria, and ribosomes.
• Common parts of a plant cell include the nucleus, cell membrane, cytoplasm, mitochondria, ribosomes, chloroplasts, cell wall, and vacuole.
• A sperm cell carries the father's genetic information to fertilize the egg.
• Adaptations of a sperm cell include a streamlined shape, one set of chromosomes in the nucleus, many mitochondria for respiration, and digestive enzymes.
• A nerve cell transmits electrical impulses around the body.
• Adaptations of a nerve cell include being long and having many dendrites to connect with other cells.
• A muscle cell contracts and relaxes to enable movement.
• Adaptations of a muscle cell include lots of mitochondria for respiration.
• Root hair cells absorb mineral ions and water from the soil.
• Adaptations of root hair cells include a large surface area and many mitochondria for respiration.
• Xylem transports water around the plant.
• Adaptations of xylem include few cell structures, being dead for more space, and being supported by lignin.
• Phloem transports sugars around the plant; few cell structures and supported by companion cells.
• Advantages of electron microscopes: higher magnification and resolution.
• Electron microscopes allow examining cells in finer detail, improving our understanding of subcellular structures.
• Magnification is calculated as: Size of Image / Size of Real Object.

B1: Cell Transport

• Diffusion is the spreading out of particles, resulting in net movement from high to low concentration areas.
• Animals and plants transport oxygen, carbon dioxide, and urea in and out of cells via diffusion.
• A greater concentration gradient increases the rate of diffusion.
• Higher temperature increases diffusion rate as particles have more kinetic energy and move faster.
• A larger surface area increases the rate of diffusion.
• Single-celled organisms are adapted for diffusion by having a large surface area to volume ratio.
• The small intestine is adapted for exchange with its length and villi providing a large surface area.
• The cell membranes of the small intestine are thin for a short diffusion pathway.
• Rich blood supply maintains a steep concentration gradient, and many mitochondria are there.
• Lungs are adapted for exchange by having many alveoli (large surface area).
• A thin membrane allows for a short diffusion pathway, with good ventilation and blood supply to maintain a steep concentration gradient.
• Gills in fish are adapted with a large surface area, thin membrane for short diffusion, and good ventilation and blood supply to maintain a steep concentration gradient.
• Roots are adapted for exchange with a large surface area, thin surface membrane, and many mitochondria for active transport.
• Leaves are adapted for exchange with a large surface area and being thin for a short diffusion pathway.
• Osmosis is the movement of water from diluted to concentrated solutions, through a partially permeable membrane.
• Active transport is the movement of substances from more diluted to more concentrated solutions, against the concentration gradient, requiring energy.
• An example of active transport in animals includes the absorption of sugar in the gut from low to high concentrations.
• An example of active transport in plants includes the absorption of mineral ions into root hair cells.

B2: Cell Division

• The nucleus contains chromosomes that are made of DNA.

• During the cell cycle:

  • The genetic material is doubled and the divided into two identical cells.
  • Then growth and mitosis occurs followed by cell division.
  • Cell needs to grow and increase the number of sub-cellular structures (ribosomes and mitochondria).
  • DNA replicates to produce two copies of each chromosome.

• During mitosis:

  • One set of chromosomes is pulled to each end of the cell.
  • The nucleus divides.
  • The cytoplasm and cell membrane divide to make two identical cells.
  • Cell division by mitosis is important for growth and development of multicellular organisms.

• A stem cell is an undifferentiated cell that can differentiate and divide to form lots of cells of the same type.

• Meristems are plant stem cells that can differentiate into any type of plant cell throughout the life of the plant.

• Plant stem cells can be used to make clones of plants quickly and economically.

• Advantages of embryonic stem cells include their ability to develop into most other cell types, dividing rapidly, and a low chance of rejection.

• Disadvantages of embryonic stem cells: they cause death to the embryo, are unreliable, and embryos can't give consent.

• Advantages of adult stem cells: permission can be given to collect stem cells, and they are safe.

• Disadvantages of adult stem cells: risk of infection from operation, painful to donate stem cells, and few types of cells.

• Some scientists have concerns about the use of stem cells because it could cause cancer.

• Sources of adult stem cells: bone marrow, umbilical cord, blood, skin.

• Stem cells from embryos are more useful than adult stem cells because they can become more types of cells.

• Therapeutic cloning involves producing an embryo with the same genes as the patient.

• Advantages of therapeutic cloning include the potential to cure diseases, produce replacement cells, treat diabetes and paralysis.

• Cells unlikely to be rejected, cells and tissues of any type can be made, many cells are produced, and reduces waiting time for transplants.

• Disadvantages of therapeutic cloning include potential life being killed, a shortage of egg donors, the potential to transfer viral infections, and a poor success rate.

• Most organisms have an even number of chromosomes in their body cells because chromosomes come in pairs.

B3: Digestion

• A tissue is a group of cells with similar structure and function.
• An organ is a group of different tissues that perform a specific function together.
• An organ system is a group of organs that work together to carry out a process in the body.
• The digestive system is an organ system that digest and absorb food.
• Enzymes are biological catalysts with a specific active site that speed up reactions.
• Enzymes work via enzymes binding to a substrate because they are complimentary shapes and the enzyme substrate complex is broken down into the product and the enzyme remains unchanged.
• At high temperatures the high temperature causes the active site to change shape so that the substrate can not fit.
• Enzymes are denatured by temperature if the temperature is too high, the forces holding the protein chains in position are affected by pH. A change in pH can change the shape of the active site.
• Amylase is made in the salivary glands, small intestine, and pancreas.
• Amylase breaks down starch into glucose.
• Protease is made in the stomach, small intestine, and pancreas.
• Protease breaks down proteins into amino acids.
• Lipase is made in the pancreas and small intestine.
• Lipase breaks down lipids into fatty acids and glycerol.
• Digestive enzymes convert food into small soluble molecules that can be absorbed into the bloodstream.
• The products of digestion are used to build new carbohydrates, lipids and proteins. Some glucose is used in respiration.
• Starch is digested in the mouth and small intestine.
• Protein is digested in the stomach and small intestine.
• Fats are digested in the small intestine.
• Starch is not digested in the stomach because the stomach doesn't produce amylase and the conditions are too acidic for amylase to work.
• The mouth breaks down starchy foods via it's teeth and the saliva contains amylase.
• Bile is made in the liver and stored in the gall bladder.
• Bile is alkaline to neutralize hydrochloric acid from the stomach and emulsifies fat to form small droplets which increases the surface area and so increases the breakdown of fat by lipase.

B4: Organization: Heart and Blood

• The heart is an organ that pumps blood around the body in a double circulatory pump.
• The heart is known as a double pump because blood enters the heart twice for one circuit around the body.
• A blood cell goes from the Body to the Vena Cava to the Right Atrium to the Right Ventricle to the Pulmonary Artery to the Lungs to the Pulmonary Vein to the Left Atrium to the Left Ventricle to the Aorta to the Body.
• The right ventricle pumps blood to the lungs where gas exchange takes place.
• The left ventricle pumps blood around the rest of the body.
• The aorta transports oxygenated blood under high pressure away from the left ventricle of the heart.
• The vena cava returns deoxygenated blood from the body to the right atrium of the heart.
• The pulmonary artery transports deoxygenated blood from the heart to the lungs.
• The pulmonary vein transports oxygenated blood from the lungs to the heart.
• Resting heart rate is controlled by a group of cells known as a pacemaker, found in the right atrium.
• Artificial pacemakers are electrical devices used to correct irregularities in the heart rate.
• Arteries transport oxygenated blood and narrow lumen and can elastic walls to withstand pressure.
• Capillaries transport blood to cells and are narrow so that blood cells pass through them one by one and have then walls for a short diffusion pathway.
• Veins transport deoxygenated blood under high pressure from the body to the heart. They have thin walls and large lumen due to low pressure and valves to prevent backflow.
• The Rate of Blood Flow is the Volume of Blood divided by the Number of Minutes.
• Blood is a tissue made up of plasma in which red blood cells, white blood cells and platelets are suspended.
• The components of blood are plasma, red blood cells, white blood cells and platelets.
• Plasma transports blood cells and different substances such as hormones around the body.
• Carbon dioxide, urea, hormones, and products of digestion are moved in blood plasma.
• Red blood cells transport oxygen around the body.
• White blood cells defend the body from infection via phagocytosis.
• WBCs defend from infection, produce antibodies, produce antitoxins

B4: Organisation: Plants

• Epidermal tissue covers the leaf.
• Palisade tissue absorbs light for photosynthesis.
• The palisade tissue is adapted for it's purpose, they are close to the upper surface of the leaf, they are packed full of chloroplasts and arranged closely together.
• The spongy mesophyll facilitates gas exchange.
• The spongy mesophyll's cells are packed loosely to allow gaps between cells and cells are covered by a thin layer of water which gases dissolve in.
• The xylem transports water and dissolved minerals around the plant.
• The xylem is adapted with a dead hollow tube strengthened by lignin.
• The phloem transports sugars around the plant
• The cells do not contain a nucleus and it is supported by companion cells. The end of each cell has a sieve plate to allow free movement of substances from cell to cell.
• Meristems are plant stem cells that differentiate into specialised cells throughout the life of the plant.
• Meristems are found in the shoots and roots.
• Stomata are small pores on the underside of the lead that allow gases to diffuse through.
• Guard cells open and close the stomata to control water loss.
• Roots provide anchorage and absorption of water and mineral ions.
• Root hair cells have a large surface area, thin surface membrane for a short diffusion pathway and lots of mitochondria.
• Roots absorb Water via osmosis and mineral ions via active transport by the roots.
• Transpiration is the transport of water through the xylem from the roots to the leaf and does not require energy.
• Translocation is the transport of sugar through the phloem both ways and requires energy.
• If temperature increases, transpiration increases because there is increased evaporation from cell surfaces and the rate of diffusion of water molecules from the lead is increased.
• If humidity decreases, tranpiration increases.
  • The increased humidity decreases the concentration gradient between water in the leaf and water in the air and so rate of diffusion of water from the leaf decreases decreases
• If air movement increases, transpiration increases.
  • The air flow removes water vapour from leaf surfaces and so more water diffuses from the leaf.
• If light intensity increases, tranpiration increases.
  • The light intensity increases the rate of photosynthesis and so stomata open so there is increased diffusion of water out of the leaf.

B5: Communicable Disease

• A communicable disease is caused by a pathogen that can be spread from one person to another.
• A non-communicable disease cannot be passed from one person to another.
• A pathogen is a microorganism that causes infectious disease.
• Pathogens can be spread through direct contact, by water, or by air.
• The spread of communicable diseases can be prevented by good hygiene such as handwashing and use of disinfectants, isolating infected people, destroying vectors that transmit the disease, and vaccination.
• Bacterial infections cause us to feel ill because the bacteria produce poisons that damage tissues.
• Viral infections cause us to feel ill because the viruses live and reproduce inside living cells which causes cell damage.
• Measles is a viral disease that causes fever and a red skin rash and is spread by droplets in coughs and sneezes. It can be fatal.
• HIV (Human Immunodeficiency Virus) is a viral disease that initially causes flu-like symptoms but then attacks the body's immune cells and is spread by sexual contact or exchange of body fluids.
• AIDS (Acquired Immune Deficiency Syndrome) is the late stage of HIV. It occurs when the body's immune system is so damaged it can no longer deal with infections or cancers.
• Tobacco mosaic virus is a plant pathogen that causes a discolouration of leaves which reduces growth as it causes less photosynthesis.
• Salmonella is a bacterial disease spread in food that causes food poisoning, it causes fever, cramps, vomiting, and diarrhoea. Gonorrhoea is a sexually transmitted bacterial disease that can cause a thick yellow discharge as well as pain when urinating.
• Rose black spot is a fungal disease in plants that causes purple or black spots on leaves and is spread by wind and water.
• Malaria is caused by protists and can cause fever and death.
• Protists are the pathogen that causes malaria.
• Malaria's spread can be prevented by preventing the mosquito from breeding and by using mosquito nets to avoid being bitten.
• The skin defends the body from pathogens by acting as a barrier and making antimicrobial secretions.
• The nose defends the body from pathogens because it’s full of hairs ,makes a sticky mucus which entrap potentially pathogenic particles.
• The trachea and bronchi defend the body from pathogens because they secrete mucus that traps pathogens. The lining is also covered in cilia that waft the mucus to the back of the throat to be swallowed.

B6: Preventing and Treating Disease

• When vaccinating a small quantity of dead or inactive forms of a pathogen are introduced into the body, the white blood cells are stimulated to make white blood cells.
• Vaccinations protect against a certain pathogen and if same pathogen re-enters body, white blood cells respond quickly to produce correct antibodies, preventing infection.
• Penicillin is an example of an antibiotic that helps cure bacterial disease by killing infective bacteria inside the body and has greatly reduced death from infectious bacterial infections.
• There is concern that antibiotics cause the emergence of strains of bacteria resistant to the antibiotics.
• Drugs that kill viruses are difficult to develop because they typically damage the body tissues also.
• Drugs were traditionally extracted from plants and microorganisms such as Foxgloves and Willow.
• Alexander Fleming discovered Penicillin which originates from Penicillium mould.
• Most new drugs are now synthesised by chemists in the pharmaceutical industry due to them needing to be safe and effective and testing for toxicity, efficacy (if it works) and dose.
• Preclinical testing is done in a lab using cells, tissues and live animals prior to the testing of new medicines.
• Clinical testing starts with healthy volunteers, followed by patients.
• Low doses of the drug are given at the start of the trial to test for safety and further trials are done to find the optimum dose.
• In a double blind trial a group are given a placebo, and another group are given the drug and neither the doctor nor the patient know who has been given what.
• Drugs are tested using a placebo in order to prove drug is effective and to avoid bias.
• Drugs are tested on animals to find if the drug is toxic and if they are to much is unsafe.

B6: Preventing and Treating Disease (H)

• The dose of a drug is the concentration of the drug to be used and how often the drug should be given. Toxicity is if the tests result in side effects.

• Efficacy is when the dug works to treat the illness.

• Monoclonal antibodies are produced from a single clone of cells and are specific to one binding site on one protein antigen.

• Production Stimulates a mouse lymphocyte to make particular antibody.

• Steps to produce monoclonal antibodies:

  • Stimulates Lymphocytes from a mouse to produce a particular antibody. -Combine the lymphocytes with a tumour cell, which leads to the creation of the hybridoma.
  • Hybridoma is cloned to produce clones of the same antibody, the antibodies are collected and purified.

• Monoclonal antibodies are combined with a lymphocyte and a tumour cell to make a hybridoma.

• Uses Pregnancy tests, detecting pathogens, measuring levels of hormones, to treat cancer.

• Monoclonal antibody is bound to a radioactive substance, a toxic drug, or a chemical that stops cells growing and dividing.

• Monoclonal antibodies are not used as widely as expected because they create more side effects than expected.

• Plant diseases can be detected by stunted growth, spots on leaves, areas of decay, growths, malformed stems or leaves, discoloration, presence of bests

• Plant diseases can be identified by referring a gardening manual or website, by using testing kits that contain monoclonal antibodies, by taking infected plants to a lab.

• Plants can be infected by insects, fungal and bacterial pathogens.

• A nitrate deficiency results in stunted growth.

• A magnesium deficiency results in chlorosis.

• Nitrate ions are needed for protein synthesis.

• Magnesium ions are needed to make chlorophyll.

• Physical defences that plants have to resist invasion of microorganisms include cellulose cell walls, tough waxy cuticle on leaves and layers of dead cells around stems which fall off.

B7: Non-Communicable Disease

• A non-communicable disease is an infectious disease that can't be caught from another person.
• A casual mechanism explains how one factor influences another.
• The risk factors of cardiovascular disease are poor diet, smoking and lack of exercise.
• The risk factors of Type 2 Diabetes are obesity.
• The risk factors of lung cancer are smoking.
• Risk factors the can affect an unborn baby are smoking and alcohol.
• Obesity is when someone with a BMI is over 25.
• Disease linked to obesity are arthritis, diabetes, high blood pressure, strokes.
• Risk factors of cancer: Carcinogens and ionising radiation
• When someone has cancer there is a non-communicable disease that is caused by a change in cells that leads to uncontrolled growth and division.
• Benign tumours are growths of abnormal cells which are contained within one area by a membrane.
• Malignant tumours are growths of abnormal cells which invade neighbouring tissues.
• Cancer travels around the body when cells break off and travel in the blood to form secondary tumours.
• Key difference between benign and malignant tumours is that Begin tumours do not invade and malignant tumours do.
• Smoking increases the risk of heart disease as it raises blood pressure, increases cholesterol, and leads to thickening of the artery walls.
• Smoking increases the risk of lung cancer as the chemicals in smoke can cause mutations leading to uncontrolled growth of cells.
• Smoking increases the risk of emphysema as smoking damages the alveoli causing the surface area to decrease, this causes shortness of breath.
• Smoking increases the risk of lung infections as the chemicals in the smoke damage the cilia which causes mucus production to increase, this causes shortness of breath and increased risk of infection.

B8: Photosynthesis

• The word equation for photosynthesis is Carbon Dioxide + Water yields Glucose + Oxygen.

• The chemical formula for:

  • carbon dioxide is CO2
  • water is H2O,
  • glucose is C6H12O6
  • oxygen is O2.

• The balanced symbol equation for photosynthesis is 6CO2 + 6H2O → C6H12O6 + 6O2.

• Photosynthesis is an endothermic reaction in which energy in the form of light is transferred from the environment to the chloroplasts.

• Factors that affect the rate of photosynthesis are:

  • Temperature
  • Light Intensity
  • Carbon Dioxide Concentration
  • Amount of Chlorophyll

• The rate of photosynthesis is affected by the factors above as outlined below:

  • The brighter the light the greater the rate of photosynthesis,
  • The greater the concentration of carbon dioxide the greater the rate of photosynthesis.
  • The more chlorophyll the greater the rate of photosynthesis.
  • When temperature keeps rising: photosynthesis increases reactant particles and enzymes collide more , but the enzymes are denatured which decreases the the rate of photosynthesis decreases.

• Rate of photosynthesis measurements are taken place after plant underwater and the volume of oxygen made (or the number of bubbles) are measured in a specific time.

• Respiration, make starch, make fats or oils, make cellulose, make amino acids.

• Plants use glucose for:

  • Amino acids made from glucose and plants which combine those with nitrate ions from soil.
    • For Storage either as starch
    • Of fat and oils, to strengthen the cell wall
  • or For Protein synthesis Chlorophyll and is to be tested and boiled in ethanol to destroy waxy cuticle and remove the colour tested is added if positive will turn blue in colour.

• These are used for respiration.

• Chloroplast

B9: Respiration

• The word equation for respiration is Glucose + Oxygen --> Carbon Dioxide + Water.
• The symbol equation for respiration is C6H12O6 + 6O2 → 6CO2 + 6H2O
• Respiration is an exothermic reaction in which energy is transferred to build larger molecules, movement and keeping warm.
• Less energy is released through anaerobic respiration compared to aerobic because the oxidation of glucose is incomplete.
• Anaerobic respiration uses oxygen, whereas aerobic respiration does not release more energy.
• In animal anaerobic respiration the word equation is Glucose -> Lactic Acid.
• In plant & yeast anaerobic respiration the word equation respiration is Glucose→ Ethanol + Carbon Dioxide.
• Anaerobic respiration in cells otherwise known as fermentation.
• Fermentation can be used to manufacture bread and alcoholic drinks.
• During exercise the heart rate, breathing rate, and breath volume increases during exercise to supply the muscles with more oxygenated blood.
• During exercise with insufficient oxygen, anaerobic respiration takes place, this leads to a build up lactic acid and creates an oxygen dept.
• Oxygen dept is the Amount of extra oxygen to remove the lactic acid from cell.
• Metabolism means the sum of all the reactions in a cell or the body which include converting glucose, forming protiens, lipids and carbs..

RP1 - Light Microscope Required Practical

• Preparing a slide you must add a drop of water, place tissue (thin layer), stain with Iodine and apply the coverslip.

• Place stained slide on stage on lowest objective lens. Using course wheel focus the image until clear. With eye piece also in focus, increase lens magnification and use fine wheel to apply finer focus.

• Iodine use cause allergic reaction or skin rash and spills MUST have ppe and should be cleaned immediately.

• Use knife while not on body (chopping board)

• Precautions during use may result in cuts.

• Lowest objective lens should be used first.

• Magnification is increased by increase power of the objective lens.

• Fine focus wheel to be turned to adjust the stage and improve image clarity.

• Magnification is calculated as length of drawing/actual length of cell.

• Electron Microscope have higher resolution and magnification.

• Ribosomes cannot be seen as they are too small.

• The length is used to measure cell in mm, and you must x1000 to covert to um.

• To improve the focus of an image when it has over magnification fine focus wheel should be turned.

Practical 1: Scopes

• Image measure should be measured as accurately and converted from mm to um and will earn addition bonus marks (1000um in 1 mm).

The equations: - Convert mm into µm - Magnification = Image length/actual length - Actual Length = Image Length/Magnification |

RP2 - Bacterial Growth Required Practical

• To produce bacterial growth:

  • Sterilize the agar and petri dish.
  • Pass sterilize and flame instruments. -Remove the lid of the dish and inoculate some bacteria from the bottle.
  • Spread bacteria and replace instruments ensuring replaced quickly. Disinfect the bench prior and post. -Secure the lid (tape) -Incubate for 24 hours at 25°C

• Measurements of radius from non-bacterial area needs to be taken.

• Replicates and sterilization must be ensure to prevent kill and maintain control variables.

• Replace cover as quickly as possible to prevent microorganisms from entering.

• Aseptic (clean/germ free) techniques should be performed.

• Dip the innoculation loop in to provide bacteria. Apply in a spread of lawn bacteria.

• Seal with tape. Upside down to pervert condensation and oxygen to breath.

• In this case, 25°C to reduce over growth and dangerous bacterial production.

• Compare to effect with zone inhibition disk (in a substance). Measurements should be taken for number of days (consistent). Control variables should also been apply. pi value 3.14

Practical 2: Bacterial Growth

• To produce methodology for bacterial growth e-coli:
  • Pour agar and sterilize.
  • sterilise bunsen. -Soak 5 disinfects on area.
  • Place another a standard of e-coli.
  • Wait seal and calculate the radius and control the measurement used.

RP3 - Osmosis Required Practical

• To carryout and measure osmosis, Balance is used to for Mass and and Stopwatch to measure time. Must remove excess post measurements prior.

To produce: the mass MUST be calculate (divide measurement by mass/multiply by 100.

• Increase: measurement and repeats. The solution dilute.
• Control: surface area/volume and control variables. Ensure consistent. Loss of mass is measure negative change, and mass: positive change.

Required Practical 3: Method

• Method to determine concentration: -Cut and trim potatoe in barrel shape in controlled intervals (5 concentrations) - Weigh -25um+0 solution for 1hr -Reweigh (with blotting and measured in percentage change). -Plot graphs to demonstrate this and find point.
• All the above method can be applied to most objects for osmosis ( Carrot, chip and egg)

RP4 - Food Tests Required Practical

• The tests required, Biuert solution for proteins is added, Iondine is added for starch and Benedict solutions added for glucose (then heated).

Practical 4: Testing

• Solid foods must crushed and mixed in solution to proceed.
• Biuert is used for proteins and results in changes in purple.
• Iodine is and in changes results in blue/black.
• Benedict heat (reduces) for orange/green.
• The most effective results when testing carbs is Amylose enzyme mixed for starch and Benedict solution for glucose.

RP5 - Investigative enzymes - Water baths should kept stable.

• A fixed volume is prepared and mixed at temperature, dropping to titrate for change. In this reaction you should have a set of variables prepared: -Indicators for lodine (startch)
  • postive or negative test
  • Enztne as amalye
• Measure with Thermerometer for temperature and stop watch time.

Results post experiment

-To determine: What, where and frequency the iodine should not reappear (blue/black) -At low and high, why woulnt enyzme work (as would be denatured and need temp) Low energy and slower reaction time. - By keeping the substances warm you all ensure all particles is at optimum teamp. Measure quickly the reaction.

RP6 - Investigating: Photosynthesis

• Setup pondweed in water and a bulb.
• Leave away the distance with light running for 5 mins and begin count bubble production/gas production. Repeat to confirm is outliers. And change the temp for measurements to confirm distance.
• During method: Light should changed, variables measured include area, ph and bulb.
• The plant needs time to stabilise with environment. Ruler ensures distance/stabilisation of temperature, (ensuring in correct environment + stable).
• Excess hydrogen carbons should be a concern and dependant vartiables with what and how long being observed.
• You can change: how long pondweed stays in and control it by the distance or temp/water content. Discs can be measured for speed or reaction time.