Which energy carriers are used to reduce 3-phosphoglycerate to glyceraldehyde-3-phosphate?

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Multiple Choice

Which energy carriers are used to reduce 3-phosphoglycerate to glyceraldehyde-3-phosphate?

NADPH provides the reducing power for this step. In the Calvin cycle, 3-phosphoglycerate is first activated by ATP, becoming 1,3-bisphosphoglycerate, and then NADPH donates a hydride to reduce it to glyceraldehyde-3-phosphate, regenerating NADP+. This specific reduction uses NADPH because it’s the form of reducing power produced by the light reactions and used for biosynthetic reductions in the chloroplast. NADH is typically used in energy-yielding pathways like glycolysis and respiration, not in this Calvin cycle reduction. FADH2 serves in other redox reactions, and ATP supplies energy for phosphorylation rather than acting as the reducing agent in this step.

NADPH provides the reducing power for this step. In the Calvin cycle, 3-phosphoglycerate is first activated by ATP, becoming 1,3-bisphosphoglycerate, and then NADPH donates a hydride to reduce it to glyceraldehyde-3-phosphate, regenerating NADP+. This specific reduction uses NADPH because it’s the form of reducing power produced by the light reactions and used for biosynthetic reductions in the chloroplast. NADH is typically used in energy-yielding pathways like glycolysis and respiration, not in this Calvin cycle reduction. FADH2 serves in other redox reactions, and ATP supplies energy for phosphorylation rather than acting as the reducing agent in this step.

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