American Society for Clinical Pathology (ASCP) Histotechnologist Practice Test

Which kind of enzyme classification involves hydrolases?

1. Transferases

2. Ligases

3. Hydrolases

4. Isomerases

The correct answer is: Hydrolases

Hydrolases are a specific class of enzymes characterized by their ability to catalyze the hydrolysis of chemical bonds. This means they facilitate the breakdown of compounds by adding water, which is a critical reaction in many biological processes. In the context of enzyme classification, the International Union of Biochemistry and Molecular Biology (IUBMB) categorizes enzymes into six major classes, which include hydrolases. Hydrolases encompass a wide range of enzymes, such as digestive enzymes like amylase and proteases, which are essential for breaking down carbohydrates and proteins, respectively. The other classifications mentioned do not focus on hydrolysis. Transferases are involved in transferring functional groups between substrates, ligases catalyze the joining of two molecules with the concomitant hydrolysis of a high-energy molecule (such as ATP), and isomerases are responsible for rearranging atoms within a molecule to form isomers. Each of these classes plays a unique role in metabolic processes, but only hydrolases specifically refer to enzymes that catalyze hydrolysis reactions.