Functional groups are specific groups of atoms within molecules that are responsible for the characteristic chemical reactions of those molecules. In toxicology, functional groups can significantly alter a molecule's reactivity and interaction with biological systems. For instance, the presence of hydroxyl groups can increase water solubility, affecting the molecule's ability to be excreted by the kidneys. On the other hand, the presence of nitro groups may increase a compound's reactivity, leading to the formation of reactive intermediates that can damage cellular structures.
