OCR Biology Photosynthesis Revision Notes
Master OCR Biology Photosynthesis using simple revision notes, key facts and practice questions — all generated by AI for your exam.
Photosynthesis is the process by which green plants, algae, and some bacteria convert light energy into chemical energy in the form of glucose. This process occurs primarily in the chloroplasts of plant cells and involves the absorption of carbon dioxide and water, releasing oxygen as a byproduct.
Key Concepts
- 1Photosynthesis occurs in two main stages: the light-dependent reactions and the light-independent reactions (Calvin cycle).
- 2Chlorophyll, the green pigment in plants, absorbs light energy, primarily in the blue and red wavelengths.
- 3The overall equation for photosynthesis is: 6CO2 + 6H2O + light energy → C6H12O6 + 6O2.
- 4Light-dependent reactions take place in the thylakoid membranes and produce ATP and NADPH.
- 5The Calvin cycle occurs in the stroma and uses ATP and NADPH to convert carbon dioxide into glucose.
Simple Explanation
Photosynthesis is how plants make their food using sunlight, carbon dioxide from the air, and water from the soil. They use a green pigment called chlorophyll to capture sunlight. This process produces glucose, which is food for the plant, and oxygen, which is released into the air. Essentially, plants turn light energy into chemical energy.
Memory Trick
“Remember 'COWS EAT LIGHT' to recall that Carbon dioxide, Water, and Sunlight are needed for Photosynthesis to produce Energy (glucose) and Oxygen.”
Flashcards
What are the two main stages of photosynthesis?
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Exam Questions
Describe and explain the light-dependent reactions of photosynthesis. [6 marks]
6 marksView mark scheme hint▾
Include details about the thylakoid membranes, light absorption, electron transport chain, ATP and NADPH production, and oxygen release.
Explain how the Calvin cycle contributes to photosynthesis. [4 marks]
4 marksView mark scheme hint▾
Discuss the role of ATP and NADPH, carbon fixation, and glucose production.
What is meant by the term 'photosynthesis'? [2 marks]
2 marksView mark scheme hint▾
Define photosynthesis and mention the role of light energy in the process.
Practice Quiz
What is the primary pigment involved in photosynthesis?
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