Final answer:
During fermentation, NAD+ is regenerated by transferring electrons from NADH to organic molecules, enabling glycolysis to continue in the absence of oxygen.
Step-by-step explanation:
During fermentation, NAD+ is recycled by transferring its electrons to a molecule other than oxygen. In the absence of oxygen, organisms must regenerate NAD+ to maintain the glycolytic pathway, an essential process for ATP production. This regeneration occurs through fermentation, where electrons from NADH are transferred to an organic molecule. This process allows glycolysis to continue but does not result in additional ATP production beyond the two ATP molecules formed in glycolysis.
By utilizing fermentation, organisms can operate in anaerobic conditions, whereby no oxygen is required for energy conversion. Common final electron acceptors in fermentation include pyruvate and acetaldehyde, which become lactic acid and ethanol, respectively.