<prompt> Which of the following enzyme is NAD dependent?HMG CoA reductaseGlycerol-3-phosphate dehydrogenaseAcyl CoA dehydrogenaseSuccinate dehydrogenase  <response>: Dehydrogenases: These enzymes cannot utilize oxygen as hydrogen acceptor. They catalyse the reversible transfer of hydrogen from one substrate to another and, thus, bring about oxidation reduction reactions. There are a large number of enzymes belonging to this groupNAD dependent dehydrogenases, e.g. alcohol dehydrogenase, glycerol 3-phosphate dehydrogenase.NADP dependent dehydrogenasese,.e.g. HMC CoA reductase ,enoyl reductase.FMN dependent dehydrogenasese,. e.g. NADH dehydrogenase.FAD dependent dehydrogenasese, e.g. succinate dehydrogenase, acyl CoA dehydrogenase.The cytochromes: All the cytochromes of electron transport chain b, c, and c except the terminal cytochrome oxidase aa3 belong to this group.Key Concept:Dehydrogenases catalyse the reversible transfer of hydrogen from one substrate to another and, thus, bring about oxidation reduction reactions.NAD dependent dehydrogenases, e.g. alcohol dehydrogenase, glycerol 3-phosphate dehydrogenaseRef : Textbook of Biochemistry, Satyanarayana 