Allopurinol prevents conversion of : a) Hypoxanthine to xanthine b) Xanthine to hypoxanthine c) Hypoxanthine to I.M.P. d) Xanthine to uric acid: (A) ab, (B) cd, (C) ad, (D) bd
Answer is C. Xanthine oxidase catalyses the conversion of hypoxanthine to xanthine as well as xanthine to uric acid. This enzyme is inhibited by allopurinol.