<prompt> All of the following are true about biotransformation except?It means chemical alteration of the drug in bodyThe primary site for drug metabolism is liverPhase I biotranformation reactions are nonsyntheticProducts of phase II biotransformation reactions are mostly active drug metabolites  <response>: Ans. is d i.e., Products of phase II biotransformation reactions are mostly active drug metab liter Biotransformation reactions metabolism of drugs can be classified : A Non-synthetic phase I reactions The new metabolite may retain biological activity or it may be an inactive metabolite. Oxidation is the most impoant metabolizing reaction. The most impoant enzyme for oxidation reaction is cytochrome P450. B Synthetic phase II or conjugation reaction Metabolism involves union of the drug with one of several polar water-soluble endogenous molecules that are products of intermediary metabolism, to form a water-soluble conjugate which is readily eliminated by kidney or, if the molecular weight exceeds 300, in the bile. Phase II metabolism almost invariably terminates biological activity, i.e. metabolites are usually inactive. 