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Photosynthesis
Study photosynthesis in AQA GCSE Biology 8461 through the photosynthetic reaction, limiting factors, required practical work, graph interpretation, and the uses of glucose made by plants.
28
Objectives
10
Flashcards
10
Questions
90 min
Study time
AqaGcseBiologyBioenergetics
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Syllabus checklist
What you need to know
28 objective pages available
Photosynthetic reaction5 objectives
- Represent photosynthesis using the word equation carbon dioxide plus water makes glucose plus oxygen.
- Represent photosynthesis using the symbol equation 6CO2 + 6H2O -> C6H12O6 + 6O2.
- Recognise the chemical symbols CO2, H2O, O2 and C6H12O6 in the photosynthesis equation.
- Describe photosynthesis as an endothermic reaction.
- Explain that light transfers energy from the environment to chloroplasts during photosynthesis.
Rate of photosynthesis15 objectives
- Explain how temperature affects the rate of photosynthesis.
- Explain how light intensity affects the rate of photosynthesis.
- Explain how carbon dioxide concentration affects the rate of photosynthesis.
- Explain how the amount of chlorophyll affects the rate of photosynthesis.
- Measure and calculate rates of photosynthesis from experimental results.
- Extract and interpret graphs of photosynthesis rate involving one limiting factor.
- Plot and draw appropriate graphs of photosynthesis rate using suitable scales for axes.
- Translate information about photosynthesis rate between graphical and numerical forms.
- Solve simple algebraic equations linked to photosynthesis rate data.
- Describe required practical activity 6: investigating the effect of light intensity on the rate of photosynthesis using an aquatic organism such as pondweed.
- Identify variables that should be controlled when investigating light intensity and photosynthesis rate.
- Explain that (HT only) temperature, light intensity, carbon dioxide concentration and chlorophyll can interact so that any one may limit photosynthesis.
- Explain graphs of photosynthesis rate involving (HT only) two or three factors and decide which factor is limiting.
- Use (HT only) inverse proportion and the inverse square law in the context of light intensity and photosynthesis.
- Use (HT only) data to relate limiting factors to the cost effectiveness of adding heat, light or carbon dioxide in greenhouses.
Uses of glucose from photosynthesis8 objectives
- Explain that glucose produced in photosynthesis may be used for respiration.
- Explain that glucose produced in photosynthesis may be converted into insoluble starch for storage.
- Explain that glucose produced in photosynthesis may be used to produce fat or oil for storage.
- Explain that glucose produced in photosynthesis may be used to produce cellulose to strengthen cell walls.
- Explain that glucose produced in photosynthesis may be used to produce amino acids for protein synthesis.
- Explain that plants need nitrate ions absorbed from the soil to produce proteins.
- Describe how qualitative reagents can be used to test for starch, glucose and proteins.
- Link the uses of glucose to plant growth, storage and cell-wall structure.
Key terms
PhotosynthesisWord Equationsymbol equationphotosynthesischemical symbolsendothermic reactionchloroplastslight energyrate of photosynthesistemperaturelight intensitycarbon dioxide concentration
Exam tips
- Master the Word Equation: Use practice writing the word equation for photosynthesis: 'carbon dioxide plus water makes glucose plus oxygen' until you can do it from memory. Link your answer to Photosynthetic reaction in Photosynthesis, and keep the biology specific to photosynthesis.
- Master the Symbol Equation: Use practice writing and balancing the symbol equation for photosynthesis: 6CO2 + 6H2O -> C6H12O6 + 6O2. Link your answer to Photosynthetic reaction in Photosynthesis, and keep the biology specific to photosynthesis.
Common mistakes
- Incorrect Word Equation Representation: Ensure to clearly write the word equation as 'carbon dioxide plus water makes glucose plus oxygen' and double-check the placement of 'plus' between each reactant and product.
- Incorrect Symbol Equation Representation: To fix this, students should practice writing the full balanced equation, ensuring they include the correct number of molecules for each reactant and product.
Practice preview
- Choose the answer that best fits the specification point: represent photosynthesis using the word equation carbon dioxide plus water makes glucose plus oxygen.?
- For Photosynthesis, which option explains "represent photosynthesis using the word equation carbon dioxide plus water makes glucose plus oxygen" most accurately?
- Which option best explains photosynthesis within Photosynthesis?
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