Photosynthesis Concepts and Processes

The video tutorial covers the AQA A-level biology topic of photosynthesis, detailing its two main stages: the light dependent and light independent reactions. It explains the structure and function of chloroplasts, the processes of photoionization, photolysis, and chemiosmosis, and the Calvin cycle. The tutorial also discusses factors that limit the rate of photosynthesis, such as temperature, CO2 concentration, and light intensity.

What are the two main stages of photosynthesis?

• Light-dependent and light-independent reactions

• Photosynthetic and respiratory reactions

• Aerobic and anaerobic reactions

• Oxidative and reductive reactions

Where does the light-dependent reaction occur?

• In the thylakoid membrane

• In the mitochondria

• In the stroma

• In the cytoplasm

What is the role of chlorophyll in the light-dependent reaction?

• It synthesizes glucose

• It releases oxygen

• It absorbs light and excites electrons

• It absorbs water

What does the term 'reduced NADP' refer to?

• NADP that has lost electrons

• NADP that has been phosphorylated

• NADP that has gained a hydrogen atom

• NADP that has been oxidized

Which enzyme catalyzes the reaction of RuBP with CO2 in the Calvin cycle?

• Phosphofructokinase

• NADP reductase

• Rubisco

• ATP synthase

What is the main product of the Calvin cycle?

• NADPH

• Glucose

• ATP

• Oxygen

How does temperature affect the rate of photosynthesis?

• Only light intensity affects the rate

• Higher temperatures always increase the rate

• It has no effect

• Enzyme activity is affected by temperature

What happens to the rate of photosynthesis at low CO2 concentrations?

• It becomes zero

• It decreases

• It remains constant

• It increases

Why is light intensity important for photosynthesis?

• It provides energy to excite electrons

• It helps in water absorption

• It is needed for glucose transport

• It cools down the plant

What is the effect of closing stomata on photosynthesis?

• Decreases water absorption

• Increases oxygen release

• Decreases CO2 intake

• Increases CO2 intake