True about drug metabolism ?: (A) Glucuronidation is phase I reaction, (B) Most common enzyme involved is Cyp 3A4/5, (C) Reduction is most common reaction, (D) Cytochrome p450 is involved phase-II reaction
Answer is B. Ans. is'b'i.e., Most common enzyme involved is Cyp 3A4/5(Ref: Katzung Ilth/e p. 55)Cytochrome p450 enzymes are microsomal enzymes that are involved in phase I metabolism of many drugs.Most of the drugs are metabolized by Cyp 3A4 isoform.Cyp 3 A 4/5 carryout biotransformation of largest number (nearly 5O%) of drugs.