Phase II reactions involve conjugation, where the metabolite from Phase I reactions is linked to an endogenous substance like glucuronic acid, sulfate, or glutathione. This process, often mediated by enzymes such as glutathione S-transferase and UDP-glucuronosyltransferase, enhances the solubility and excretion of the xenobiotic. Phase II reactions generally render substances less toxic, although certain conjugates can still be reactive and harmful.
