20 Why is it critical that NAD* and FAD be regenerated inside themitochondrial matrix rather than the cytosol?Because they maintain flux through the citrate cycle.Because anabolic reactions generally require them.Because they transport pyruvate through the matrix.Because they produce GDP through the citrate cycle.

NAD+ and FAD are coenzymes derived from vitamin B3 and vitamin B2 respectively. Both NAD+ and FAD are coenzymes utilized by oxidation-reduction reactions. They accept electrons produced during various metabolic pathways and transport the electrons in the electron transport chain, which ultimately leads to energy synthesis. NAD+ and FAD are regenerated inside the mitochondrial matrix rather than the cytosol because, most of the NAD+ and FAD that are regenerated through the electron transport chain enter into the citrate cycle and accepts more electrons for energy synthesis. Thus, the answer is, A) Because they maintain the flux through the citrate cycle. B) Because anabolic reactions generally require them - Incorrect. Because anabolic reactions majorly use NADP+ as the coenzyme. C) Because they transport pyruvate through the matrix - Incorrect. Pyruvate is transported from the cytosol to the mitochondrial matrix through specific transport proteins. D) Because they produce GDP through the citrate cycle - Incorrect. In the citric acid cycle, NAD+ and FAD get converted into their reduced forms NADH and FADH2 respectively. And they do not participate in the synthesis of GDP. Answer: A) Because they maintain the flux through the citrate cycle.