Once a chemical enters the body, it undergoes metabolic processes primarily in the liver, although other organs can be involved. These processes are generally categorized into two phases: Phase I and Phase II metabolism.
- Phase I Metabolism: This involves chemical modifications like oxidation, reduction, or hydrolysis, often mediated by enzymes such as the cytochrome P450 family. The purpose is to introduce or expose a functional group on the compound, making it more reactive for Phase II.
- Phase II Metabolism: In this phase, the reactive compound is conjugated with hydrophilic molecules, making it more water-soluble and easier to excrete via urine or bile. Common conjugation reactions involve glucuronidation, sulfation, and acetylation.
