Which dietary vitamin is required for transaminase reactions?: (A) Thiamine, (B) Folic acid, (C) Pyridoxine, (D) Cyanocobalamin
Answer is C. Pyridoxal phosphate paicipates in transamination by cycling between the pyridoxal and pyridoxamine forms. Thiamine is a cofactor for transketolase and the -ketoacid dehydrogenases. Folate functions in single carbon transfer reactions. Vitamin B12 functions in methionine synthase and methylmalonyl CoA mutase.