How do Phase II Reactions Differ from Phase I Reactions?
Phase I reactions primarily involve the introduction or exposure of a functional group on the substrate, making it more reactive. These reactions are usually catalyzed by enzymes such as cytochrome P450s (CYPs). In contrast, Phase II reactions involve the conjugation of a small, polar molecule to the substrate, significantly increasing its water solubility. While Phase I reactions can sometimes produce reactive and potentially toxic intermediates, Phase II reactions generally result in less toxic and more easily excreted products.
