In the context of toxicology, enzymes are essential for the metabolism of xenobiotics, which are foreign substances like drugs, pollutants, and toxins. The primary role of these enzymes is to convert lipophilic compounds into more hydrophilic forms, making them easier to excrete. This process often occurs in two phases:
1. Phase I Reactions: These involve oxidation, reduction, or hydrolysis, primarily mediated by the cytochrome P450 family of enzymes. These reactions introduce or expose functional groups on the xenobiotics. 2. Phase II Reactions: These involve conjugation reactions where the functional groups introduced in Phase I are linked with endogenous molecules like glucuronic acid, sulfate, or glutathione. This further increases the solubility of the compounds.
