Question

question 11 of 25
how do the light reactions and calvin cycle work together to build glucose?
a. the calvin cycle provides excited electrons to the light reactions.
b. the light reactions provide the energy carriers used in the calvin cycle.
c. the light reactions provide the calvin cycle with glucose molecules.
d. the calvin cycle provides atp to the light reactions.

Explanation:

• Light reactions:
• Occur in the thylakoid membranes of chloroplasts.
• Convert light energy into chemical energy in the form of ATP (adenosine triphosphate) and NADPH (nicotinamide adenine dinucleotide phosphate - reduced).
• Calvin cycle:
• Takes place in the stroma of chloroplasts.
• Uses the ATP and NADPH (energy carriers) from the light reactions to fix carbon dioxide ($CO_2$) and produce glucose.
• Option A: The Calvin cycle does not provide excited electrons to the light reactions. The light reactions get excited electrons from water splitting.
• Option B: The light reactions provide energy carriers (ATP and NADPH) to the Calvin cycle, not the other way around.
• Option D: The Calvin cycle produces glucose, it does not provide ATP to the light reactions. The light reactions produce ATP.

Answer:

C. The light reactions provide the Calvin cycle with energy carriers used in the Calvin cycle.