All of the following are characteristics of phenylalanine hydroxylase, EXCEPT: (A) Mixed function oxidase, (B) Tetrahydrobiopterin is a cofactor, (C) NADPH provides the reducing power, (D) Vitamin C is a cofactor
Answer is D. PAH is a mixed-function oxidase because it incorporates one atom of oxygen into phenylalanine and another atom of oxygen into H2 to form H2O. Remember: Not all hydroxylase enzymes require Vitamin C. Not all carboxylase enzymes require Vitamin K.