The two steps in photosynthesis are the light-dependent reactions and the Calvin cycle.

Question

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 Calvin cycle converts water molecules into oxygen gas as a byproduct of its reactions.
d
The light-dependent reactions take place in the thylakoid membrane, and the Calvin cycle takes place in the stroma.

Answer 1

The correct statement regarding the two steps of photosynthesis is:

d 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; this occurs in the Calvin cycle, where ATP and NADPH produced in the light-dependent reactions are used to convert carbon dioxide into sugars.

b. The light-dependent reactions do not use ATP from the Calvin cycle; rather, they produce ATP and NADPH that are then used in the Calvin cycle.

c. The Calvin cycle does not convert water molecules into oxygen gas; this process occurs during the light-dependent reactions, where water is split, producing oxygen as a byproduct.