What role does NAD+ and NADH play in cellular respiration? How is fermentation related to cellular respiration? Explain.

Answer 1

NAD+ is an electron carrier which will pick up electrons during the course of cellular respiration. When NAD+ picks up an electron, it becomes reduced, and becomes NADH. NADH carries electrons all the way to the Electron Transport Chain, where it will then drop off the electrons. This will allow for the powering of protons to be pumped across a concentration gradient, which then allows ATP Synthase to churn, producing ATP in the end.

As for fermentation, remember that it only occurs in anaerobic conditions, so it occurs when cellular respiration is not possible. Both fermentation and cellular respiration require glycolysis though, an anaerobic process, which turns 1 Glucose into 2 Pyruvates. What occurs next is what differs. After glycolysis for fermentation, either 2 Lactates can be formed (in Lactic Acid Fermentation) or 2 Ethanols can be formed (in Alcohol Fermentation). The big point of fermentation is to regenerate NAD+ in the presence of no oxygen.