What is the end product of pyruvate reduction by NADH?

The end product of pyruvate reduction by NADH is indeed lactate. This process occurs under anaerobic conditions, where the conversion of pyruvate to lactate helps regenerate NAD+, which is essential for the continuation of glycolysis, allowing for ATP production when oxygen is scarce.

During this reaction, pyruvate, which is produced at the end of glycolysis, is reduced to lactate by the enzyme lactate dehydrogenase. NADH donates electrons to pyruvate, and in doing so, it becomes oxidized back to NAD+. This is crucial because the regeneration of NAD+ allows glycolysis to persist, even in the absence of oxygen. The buildup of lactate in muscles during intense exercise is a classic example of this process, which can lead to muscle fatigue.

In contrast, the other options represent different metabolic pathways following pyruvate's formation:

• Oxaloacetate is produced from pyruvate in gluconeogenesis or as a part of the citric acid cycle but is not directly formed through the reduction of pyruvate.
• Glucose is synthesized through gluconeogenesis from pyruvate substrates but is not the end product of the reduction of pyruvate.
• Acetyl-CoA