Which glycolytic enzyme catalyzes the step that reduces NAD+ to NADH?

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Multiple Choice

Which glycolytic enzyme catalyzes the step that reduces NAD+ to NADH?

NADH production in glycolysis occurs at the glyceraldehyde-3-phosphate dehydrogenase step. In this reaction, glyceraldehyde-3-phosphate is oxidized and simultaneously combines with inorganic phosphate to form 1,3-bisphosphoglycerate. The oxidation donates electrons to NAD+, reducing it to NADH. This step links oxidation of the substrate to substrate-level phosphorylation that follows, helping drive ATP formation later in glycolysis. The other enzymes listed do not involve NAD+ reduction: hexokinase uses ATP to phosphorylate glucose, phosphofructokinase-1 uses ATP to convert fructose-6-phosphate to fructose-1,6-bisphosphate, and pyruvate kinase generates ATP from phosphoenolpyruvate without changing NAD+.

NADH production in glycolysis occurs at the glyceraldehyde-3-phosphate dehydrogenase step. In this reaction, glyceraldehyde-3-phosphate is oxidized and simultaneously combines with inorganic phosphate to form 1,3-bisphosphoglycerate. The oxidation donates electrons to NAD+, reducing it to NADH. This step links oxidation of the substrate to substrate-level phosphorylation that follows, helping drive ATP formation later in glycolysis. The other enzymes listed do not involve NAD+ reduction: hexokinase uses ATP to phosphorylate glucose, phosphofructokinase-1 uses ATP to convert fructose-6-phosphate to fructose-1,6-bisphosphate, and pyruvate kinase generates ATP from phosphoenolpyruvate without changing NAD+.

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