Correct option is D
The correct answer is option (d): NADPH is produced during carbon reactions by the enzymes present in the stroma. This statement is incorrect because NADPH is actually produced during the light reactions of photosynthesis, not during the carbon reactions (Calvin cycle). The light reactions occur in the thylakoid membranes of the chloroplasts, where NADP+ is reduced to NADPH, and ATP is also produced through photophosphorylation.
Let’s break down the other options to see why they are correct:
Option (a): Light reactions (also called the light-dependent reactions) do take place in the thylakoid membranes. These reactions use light energy to produce ATP and NADPH, which are then used in the Calvin cycle to fix carbon.
Option (b): ATP and NADPH are produced in the thylakoid membranes during the light reactions of photosynthesis. ATP is generated by phosphorylation (using energy from light), and NADPH is generated by the reduction of NADP+.
Option (c): The lumen is the enclosed region inside the thylakoid membranes, and it is where the protons (H+) accumulate during the light reactions. This proton gradient is essential for the production of ATP by the ATP synthase complex.
