Why is Pyruvate Reduced During Fermentation

Question

Why is pyruvate reduced during fermentation? A) to regenerate NAD⁺, permitting glycolysis to continue B) to produce additional NADH, which can be oxidized in electron transport C) to produce additional ATP by coupling ATP production to the reduction of pyruvate. The now reduced form of pyruvate can then enter the Krebs Cycle. D) Pyruvate is toxic to cells. It is therefore reduced to a non-toxic form.

Accepted Answer

Pyruvate is reduced during fermentation to regenerate NAD+ for glycolysis to continue in the absence of oxygen. This is necessary because NAD+ is required as an electron acceptor for the conversion of glyceraldehyde-3-phosphate to 1,3-bisphosphoglycerate, which generates ATP. Without pyruvate reduction, NAD+ would become depleted and glycolysis would stop.