[Campbell Biology P.247] Which of the following statements correctly differentiates between ... | Practice Question

Which of the following statements correctly differentiates between linear and cyclic electron flow in photosynthesis?

  • A: Linear electron flow primarily produces ATP and NADPH, while cyclic electron flow primarily produces ATP.
  • B: Both linear and cyclic electron flows involve Photosystem II.
  • C: Cyclic electron flow is essential for generating the proton gradient, whereas linear flow is not.
  • D: NADPH is a product of cyclic electron flow but not linear electron flow.

Explanation

Linear electron flow generates both ATP and NADPH, which are crucial for the Calvin cycle. In contrast, cyclic electron flow primarily serves to supplement ATP production via chemiosmosis by shunting electrons back from Photosystem I to the cytochrome complex, and it does not produce NADPH. This is clearly stated in the text regarding both processes and their outcomes.