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
The Calvin cycle converts water molecules into oxygen gas as a byproduct of its reactions.
b
The light-dependent reactions take place in the thylakoid membrane, and the Calvin cycle takes place in the stroma.
c
During the light-dependent reactions, carbon dioxide is fixed to produce sugars that form glucose.
d
The light-dependent reactions use ATP from the Calvin cycle, and the Calvin cycle uses energy from absorbed sunlight.
Which of the following is true regarding these two steps?
a
The Calvin cycle converts water molecules into oxygen gas as a byproduct of its reactions.
b
The light-dependent reactions take place in the thylakoid membrane, and the Calvin cycle takes place in the stroma.
c
During the light-dependent reactions, carbon dioxide is fixed to produce sugars that form glucose.
d
The light-dependent reactions use ATP from the Calvin cycle, and the Calvin cycle uses energy from absorbed sunlight.
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.
To clarify the other options:
- **a** is incorrect because the Calvin cycle does not convert water molecules into oxygen; that process occurs during the light-dependent reactions.
- **c** is incorrect because carbon dioxide is fixed and sugars are produced in the Calvin cycle, not during the light-dependent reactions.
- **d** is incorrect because the light-dependent reactions produce ATP (and NADPH) using energy from sunlight, while the Calvin cycle utilizes that ATP (and NADPH) to fix carbon dioxide and synthesize sugars; they do not use ATP from the Calvin cycle.
**b**: The light-dependent reactions take place in the thylakoid membrane, and the Calvin cycle takes place in the stroma.
To clarify the other options:
- **a** is incorrect because the Calvin cycle does not convert water molecules into oxygen; that process occurs during the light-dependent reactions.
- **c** is incorrect because carbon dioxide is fixed and sugars are produced in the Calvin cycle, not during the light-dependent reactions.
- **d** is incorrect because the light-dependent reactions produce ATP (and NADPH) using energy from sunlight, while the Calvin cycle utilizes that ATP (and NADPH) to fix carbon dioxide and synthesize sugars; they do not use ATP from the Calvin cycle.