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 use ATP from the Calvin cycle, and the Calvin cycle uses energy from absorbed sunlight. c The light-dependent reactions take place in the thylakoid membrane, and the Calvin cycle takes place in the stroma. 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:
**c. The light-dependent reactions take place in the thylakoid membrane, and the Calvin cycle takes place in the stroma.**
Here's a brief explanation of why the other options are incorrect:
a. During the light-dependent reactions, carbon dioxide is not fixed; rather, these reactions capture light energy to produce ATP and NADPH. The fixation of carbon dioxide occurs during the Calvin cycle.
b. The light-dependent reactions do not use ATP from the Calvin cycle; instead, they generate ATP and NADPH that the Calvin cycle uses to synthesize sugars.
d. The Calvin cycle does not convert water molecules into oxygen gas; oxygen is produced as a byproduct of the light-dependent reactions when water is split (photolysis).
Thus, option c is the accurate statement about the photosynthesis process.
**c. The light-dependent reactions take place in the thylakoid membrane, and the Calvin cycle takes place in the stroma.**
Here's a brief explanation of why the other options are incorrect:
a. During the light-dependent reactions, carbon dioxide is not fixed; rather, these reactions capture light energy to produce ATP and NADPH. The fixation of carbon dioxide occurs during the Calvin cycle.
b. The light-dependent reactions do not use ATP from the Calvin cycle; instead, they generate ATP and NADPH that the Calvin cycle uses to synthesize sugars.
d. The Calvin cycle does not convert water molecules into oxygen gas; oxygen is produced as a byproduct of the light-dependent reactions when water is split (photolysis).
Thus, option c is the accurate statement about the photosynthesis process.