How does the formation of NAD+ differ between aerobic and anaerobic respiration? A. NAD+ is formed in aerobic respiration by a fermentation process and formed in anaerobic respiration by oxidation of NADH.

B. NAD+ is formed by a fermentation process in anaerobic respiration by the conversion of pyruvate into lactate and by simple oxidation of NADH in aerobic respiration.

C. Under aerobic conditions, the electron acceptor is a molecule other than oxygen for NAD+ production, whereas under anaerobic conditions the electron acceptor is oxygen.

D. NAD+ is formed by the breakdown of pyruvate to form oxaloacetate in anaerobic respiration whereas in aerobic respiration it is formed by the breakdown of pyruvate into lactic acid or alcohol.

B. NAD+ is formed by a fermentation process in anaerobic respiration by the conversion of pyruvate into lactate and by simple oxidation of NADH in aerobic respiration.

Explanation:

Nicotinamide adenine dinucleotide (NAD) is an important coenzyme that may exist in two different forms: oxidized (NAD+) and reduced (NADH). The fermentation is an anaerobic oxidation-reduction reaction where pyruvate and NADH are reactants, while lactate and NAD+ are products generated by the oxidation of NADH to NAD+ and pyruvate to lactate, respectively. On the other hand, during aerobic respiration, NADH generated by glycolysis is oxidized to form NAD+ by the donation of its electrons to reduce pyruvate to lactate. Subsequently, NAD+ is reused in glycolysis (again) in order to generate more molecules of ATP.