Question
The two main steps in photosynthesis are the light-dependent reactions and the Calvin cycle. Which of the following is true regarding these two steps? a During the light-dependent reactions, carbon dioxide is fixed to produce sugars that form glucose. b The light-dependent reactions take place in the thylakoid membrane, and the Calvin cycle takes place in the stroma. c The light-dependent reactions use ATP from the Calvin cycle, and the Calvin cycle uses energy from absorbed sunlight. d The Calvin cycle converts water molecules into oxygen gas as a byproduct of its reactions.
Answers
GPT-4o mini
The correct statement regarding the two main steps in photosynthesis is:
**b) The light-dependent reactions take place in the thylakoid membrane, and the Calvin cycle takes place in the stroma.**
Here's a brief explanation for why the other statements are incorrect:
a) This statement is false because carbon dioxide is fixed during the Calvin cycle, not during the light-dependent reactions.
c) This statement is misleading. The light-dependent reactions produce ATP (and NADPH), which are then used in the Calvin cycle. The Calvin cycle does not produce ATP; instead, it uses ATP and NADPH generated from the light-dependent reactions.
d) This statement is false because the Calvin cycle does not convert water molecules into oxygen gas; rather, oxygen is produced as a byproduct of the light-dependent reactions when water is split.
**b) The light-dependent reactions take place in the thylakoid membrane, and the Calvin cycle takes place in the stroma.**
Here's a brief explanation for why the other statements are incorrect:
a) This statement is false because carbon dioxide is fixed during the Calvin cycle, not during the light-dependent reactions.
c) This statement is misleading. The light-dependent reactions produce ATP (and NADPH), which are then used in the Calvin cycle. The Calvin cycle does not produce ATP; instead, it uses ATP and NADPH generated from the light-dependent reactions.
d) This statement is false because the Calvin cycle does not convert water molecules into oxygen gas; rather, oxygen is produced as a byproduct of the light-dependent reactions when water is split.