Phase 2 metabolism involves which process?

Phase 2 metabolism involves which process?

• A. Conjugation to attach a polar molecule
• B. Oxidation to introduce functional groups
• C. Hydrolysis to break down bonds
• D. Reduction to increase lipophilicity

Answer: (A)

Phase 2 metabolism centers on conjugation reactions that attach a polar group to the drug or its Phase 1 metabolite, producing highly water-soluble products ready for excretion. This is why conjugation to attach a polar molecule is the best description: the goal is to increase hydrophilicity so the compound can be readily eliminated by the kidneys or biliary system. Common conjugation pathways include glucuronidation, sulfation, and glutathione (or amino acid) conjugation, each adding a polar moiety to the molecule. Oxidation, hydrolysis, and reduction are typically Phase 1 processes that modify the molecule or introduce functional groups to set up sites for further metabolism. They are not the conjugation step that characterizes Phase 2.

Phase 2 metabolism centers on conjugation reactions that attach a polar group to the drug or its Phase 1 metabolite, producing highly water-soluble products ready for excretion. This is why conjugation to attach a polar molecule is the best description: the goal is to increase hydrophilicity so the compound can be readily eliminated by the kidneys or biliary system. Common conjugation pathways include glucuronidation, sulfation, and glutathione (or amino acid) conjugation, each adding a polar moiety to the molecule.

Oxidation, hydrolysis, and reduction are typically Phase 1 processes that modify the molecule or introduce functional groups to set up sites for further metabolism. They are not the conjugation step that characterizes Phase 2.