What is the significance of the light-dependent reactions in photosynthesis?
Practice Questions
Q1
What is the significance of the light-dependent reactions in photosynthesis?
They produce glucose directly
They generate ATP and NADPH for the Calvin cycle
They fix carbon dioxide
They release carbon dioxide
Questions & Step-by-Step Solutions
What is the significance of the light-dependent reactions in photosynthesis?
Correct Answer: Light-dependent reactions generate ATP and NADPH.
Step 1: Understand that photosynthesis is the process plants use to make food using sunlight.
Step 2: Know that photosynthesis has two main parts: light-dependent reactions and the Calvin cycle.
Step 3: Light-dependent reactions happen in the thylakoid membranes of chloroplasts when sunlight hits the plant.
Step 4: During these reactions, sunlight energy is used to split water molecules, releasing oxygen.
Step 5: The energy from sunlight is also used to create two important molecules: ATP and NADPH.
Step 6: ATP (adenosine triphosphate) is like energy currency for the cell, providing energy for various processes.
Step 7: NADPH is a carrier of electrons and hydrogen, which are used in the next part of photosynthesis.
Step 8: The Calvin cycle, which occurs in the stroma of chloroplasts, uses ATP and NADPH to convert carbon dioxide into glucose (sugar).
Step 9: Therefore, the light-dependent reactions are significant because they produce the energy and reducing power needed for the Calvin cycle to make food.
