Lyases are a type of enzyme that catalyze the breaking of chemical bonds in molecules without the addition of water, which distinguishes them from other enzymes like hydrolases. They often facilitate the formation of double bonds or rings by removing groups from substrates. These enzymes play crucial roles in various metabolic pathways, including the breakdown of carbohydrates and amino acids. For example, decarboxylases are a specific type of lyase that remove carboxyl groups from amino acids, contributing to the production of important biological compounds.