Question

which of the following best describes the function of the coenzymes nad and fad in eukaryotic cellular respiration?
a they participate in hydrolysis reactions by accepting protons from water molecules.
b they participate directly in the phosphorylation of adp to atp.
c they serve as final electron acceptors in the electron transport chain.
d they aid vitamins such as niacin in the breakdown of glucose.
e they accept electrons during oxidation - reduction reactions

Explanation:

• Option A: Hydrolysis reactions involve water splitting, but \(NAD^{+}\) and \(FAD\) are not mainly about accepting protons from water in cellular respiration.
• Option B: The phosphorylation of ADP to ATP is mainly related to ATP synthase and proton - motive force, not directly \(NAD^{+}\) and \(FAD\).
• Option C: Oxygen is the final electron acceptor in the electron transport chain in eukaryotic cellular respiration.
• Option D: \(NAD^{+}\) and \(FAD\) are coenzymes, not aiding vitamins like niacin in glucose breakdown in this context.
• Option E: In cellular respiration, during oxidation - reduction reactions (e.g., in glycolysis, citric acid cycle), \(NAD^{+}\) accepts electrons to become \(NADH\) and \(FAD\) accepts electrons to become \(FADH_{2}\). These reduced coenzymes then donate electrons to the electron transport chain.

Answer:

E. They accept electrons during oxidation - reduction reactions.