Key term
AQA GCSE Biology 8461
Bioenergetics
Cell Biology
Topic overviewEukaryotes and prokaryotesAnimal and plant cellsCell specialisation and differentiationMicroscopyGrowing bacteria and aseptic techniqueCalculating bacterial growth, and testing antiseptics and antibioticsChromosomes, mitosis and the cell cycleStem cells in embryos, adults and meristemsTherapeutic cloning, its risks, and cloning plantsDiffusion and the factors affecting its rateSurface area to volume ratio and exchange surfacesOsmosisActive transport
Ecology
Topic overviewLevels of organisation in an ecosystem, and what organisms needCompetition, interdependence and stable communitiesAbiotic factorsBiotic factorsAdaptationsProducers, food chains and sampling with quadrats and transectsPredators, prey and measuring population sizeHow materials are cycledDecompositionWaste management and biodiversityLand use, deforestation and global warmingMaintaining biodiversityTrophic levels and pyramids of biomassTransfer of biomassFactors affecting food securityFarming techniques and sustainable fisheriesRole of biotechnologyImpact of environmental change
Homeostasis and Response
Topic overviewHomeostasisThe nervous system and the reflex arcThe structure of the eye and accommodationMyopia, hyperopia and how they are correctedThe brain and the control of body temperatureHuman endocrine systemInsulin, glucagon and diabetesWater and ion loss, and the production of ureaThe kidneys, ADH and treating kidney failureHormones in human reproductionContraceptionThe use of hormones to treat infertilityNegative feedbackPlant hormones and their uses
Infection and Response
Topic overviewCommunicable (infectious) diseasesViral diseasesBacterial diseasesFungal and protist diseasesHuman defence systemsVaccinationAntibiotics and painkillersDiscovery and development of drugsProducing monoclonal antibodiesUses of monoclonal antibodiesDetection and identification of plant diseasesPlant defence responses
Inheritance, Variation and Evolution
Topic overviewSexual and asexual reproductionMeiosisAdvantages and disadvantages of sexual and asexual reproductionDNA and the genomeDNA as a polymer of four nucleotidesProtein synthesis and complementary base pairingMutations, protein shape and non-coding DNAGenetic terms, dominant and recessive allelesPunnett squares, probability and genetic crossesInherited disorders and sex determinationVariationEvolutionSelective breedingWhat genetic engineering is, and what it is used forGM crops, their risks, and the steps of the processCloningDarwin, Lamarck and the acceptance of evolutionSpeciationThe understanding of geneticsEvidence for evolution, and extinctionFossilsResistant bacteriaClassification of living organisms
Organisation
Topic overviewLevels of organisation, and how enzymes workAmylase, proteases and lipasesBile, food tests and the effect of pH on amylaseThe heart, the lungs and double circulationThe pacemaker, the blood vessels and the bloodCoronary heart disease: a non-communicable diseaseHealth issuesRisk factors and causal mechanisms in diseaseSampling, correlation and interpreting risk dataCancerPlant tissues, and transpiration and its rateRoot hair cells, xylem, phloem and stomata
Bioenergetics
- 6 subtopics
- 18 things to know
- Paper 1
What Bioenergetics covers
Bioenergetics is examined in Biology Paper 1. It covers the photosynthesis reaction and the uses of glucose, the rate of photosynthesis, why organisms respire and how aerobic and anaerobic respiration differ, the equations for respiration and fermentation, the response to exercise, and metabolism.
Where it is assessed
Paper 1
Biology Paper 1: 1 hour 45 minutes, 100 marks, 50% of the GCSE.
Check the AQA specification ↗The 6 subtopics
Each one has its own page.
- The photosynthesis reaction and the uses of glucoseThe word equation and chemical formulae for photosynthesis, why it is endothermic and needs light energy transferred to the chloroplasts, how glucose is used for respiration, starch, fat or oil, cellulose and amino acids, and the nitrate ions needed to make proteins.Open →
- Rate of photosynthesisHow light intensity, carbon dioxide, temperature and chlorophyll affect the rate, calculating and graphing a rate from bubble counts, limiting factors on graphs, the inverse square law, greenhouse costs, the pondweed investigation with its controls, gas syringe and hazards, writing and testing a hypothesis, and rates from tangents.Open →
- Why organisms respire, and aerobic versus anaerobicRespiration as a continuous exothermic reaction in all living cells, the energy it supplies, aerobic against anaerobic respiration in oxygen use, energy transferred and products, why muscles respire anaerobically, and energy used for building molecules, movement and keeping warm.Open →
- The equations for respiration, and fermentationThe word equation and formulae for aerobic respiration, anaerobic respiration in muscle producing lactic acid and why it transfers less energy, anaerobic respiration in yeast and plant cells producing ethanol and carbon dioxide, and fermentation in bread and alcoholic drinks.Open →
- Response to exerciseWhy energy demand rises during exercise, the extra glucose and oxygen delivered, increases in heart rate, breathing rate and breath volume, anaerobic respiration and lactic acid, muscle fatigue, oxygen debt, and how the liver converts lactic acid back into glucose.Open →
- MetabolismThe building blocks of carbohydrates, proteins and lipids, metabolism as the sum of enzyme-controlled reactions powered by respiration, glucose converted to starch, glycogen and cellulose, lipids from glycerol and fatty acids, amino acids from glucose and nitrate, and excess protein broken down to urea.Open →
What you need to know
Answer each one before you reveal it.
Your recallNot started
Key term
Describe where respiration takes place, why an organism cannot survive without respiration, and how aerobic and anaerobic respiration differ.
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State the word equation for anaerobic respiration in yeast, how yeast and muscle differ in their products, and how fermentation makes bread rise.
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State the word equation for photosynthesis.
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Explain why the body's demand for energy rises during exercise.
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Which smaller molecules are carbohydrates built up from and broken down into?
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What supplies the energy that drives photosynthesis?
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Describe the effect of increasing light intensity on the rate of photosynthesis.
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A student says that only animals respire. Explain why this is wrong.
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State the word equation for aerobic respiration.
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Which two substances must be delivered to the muscles in greater amounts when a person starts to exercise?
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Name the two kinds of smaller molecule that lipids are broken down into.
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Give the chemical formulae of carbon dioxide, water, oxygen and glucose.
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Explain why raising the carbon dioxide concentration around a plant can increase its rate of photosynthesis.
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Explain why an organism cannot survive if respiration stops in its cells.
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Name the two reactants used up in aerobic respiration.
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Give three changes in the heart and lungs that occur during exercise.
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Explain why a cell needs a supply of amino acids.
Take Bioenergetics further
The same content, four other ways.
Commonly confused
Pairs that lose marks when they are blurred together.
Aerobic respiration vs Anaerobic respiration
Aerobic respiration: the breakdown of glucose using oxygen, transferring much more energy. Anaerobic respiration: the breakdown of glucose without oxygen, transferring much less energy.
Endothermic vs Exothermic
Endothermic: a change that needs energy transferred in, as photosynthesis does from light. Exothermic: a change that transfers energy out to the surroundings, as respiration does.
Photosynthesis vs Respiration
Photosynthesis: the process in which plants make glucose from carbon dioxide and water using light. Respiration: the process in which every living cell transfers energy by breaking down glucose.
Questions from this topic
Each one with the model answer underneath.
- 1
State the word equation for photosynthesis.
Model answer
Carbon dioxide + water → glucose + oxygen.
- 2
What supplies the energy that drives photosynthesis?
Model answer
Light from the environment.
- 3
Give the chemical formulae of carbon dioxide, water, oxygen and glucose.
Model answer
CO₂, H₂O, O₂ and C₆H₁₂O₆.
- 4
Explain why photosynthesis is described as an endothermic reaction.
Model answer
Because energy is taken in from the environment during the reaction rather than released.
- 5
Into which structures of a plant cell is energy transferred by light during photosynthesis?
Model answer
The chloroplasts.
- 6
A potted plant is left in a completely dark cupboard. Explain why it cannot photosynthesise.
Model answer
Photosynthesis is endothermic and needs energy transferred to the chloroplasts by light, so with no light the reaction cannot take place.
What is inside Levo
Six ways to work the same material.
Bioenergetics revision questions
- What does Bioenergetics cover in AQA GCSE Biology?
- 6 subtopics: the photosynthesis reaction and the uses of glucose, rate of photosynthesis, why organisms respire, and aerobic versus anaerobic, the equations for respiration, and fermentation, response to exercise and metabolism. Each one has its own page with questions and model answers.
- How is Bioenergetics organised?
- By the AQA 8461 specification, subtopic by subtopic, so it matches the order you are taught it in.
Every question in Bioenergetics, on a schedule.
Attempt a question from memory, write the correct version, then attempt it again. Levo records the jump between your first attempt and your last, and brings each question back on the day you are due to forget it.
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