When a suspension of algae is incubated in a flask in the presence of light and CO₂ and then transferred to the dark,the reduction of 3-phosphoglycerate to glyceraldehyde 3-phosphate is blocked.This reaction stops in the dark because

Question

Quizplus · Accepted Answer

The reduction of 3-phosphoglycerate to glyceraldehyde 3-phosphate is a part of the Calvin cycle, which requires ATP and NADPH produced during the light-dependent reactions of photosynthesis. In the absence of light, this reaction stops due to the lack of ATP and NADPH. Choice A is incorrect as CO₂ is not required for this specific reaction. Choice B is incorrect as the exergonic nature of the reaction does not explain why the reaction stops in the dark. Choice D is incorrect as the reaction does not require O₂ for this specific step. Choice E is irrelevant to the question.

When a Suspension of Algae Is Incubated in a Flask