What type of reactions do lyases typically catalyze?

Lyases are enzymes that catalyze the addition or cleavage of chemical bonds without the involvement of water (which would characterize hydrolytic reactions) or the transfer of electrons (as seen in oxidation-reduction reactions). Instead, they facilitate reactions that result in the formation of double bonds or the breaking of chemical bonds to generate products that have one or more new functional groups.

For example, a lyase might catalyze the conversion of a compound by either adding a group across a double bond or removing a group to create a double bond. This unique ability to perform both addition and cleavage reactions sets lyases apart from other enzyme classes, such as hydrolases, which specifically involve the addition of water in their reactions. Consequently, the correct characterization of lyases as catalysts of addition or cleavage reactions highlights their essential role in metabolic pathways where such transformations are required for metabolic processes.