American Society for Clinical Pathology (ASCP) Histotechnologist Practice Test

How many basic classifications of enzyme reactions are recognized?

1. Four

2. Five

3. Six

4. Seven

The correct answer is: Six

The correct classification of enzyme reactions recognizes six basic types. These classifications are essential for understanding the various biochemical processes that enzymes facilitate in the body. The six classifications include: 1. **Oxidoreductases** - enzymes that catalyze oxidation-reduction reactions. 2. **Transferases** - enzymes that transfer functional groups from one molecule to another. 3. **Hydrolases** - enzymes that catalyze hydrolysis reactions, breaking down compounds with the addition of water. 4. **Lyases** - enzymes that catalyze the addition or removal of groups to form double bonds. 5. **Isomerases** - enzymes that catalyze the rearrangement of atoms within a molecule. 6. **Ligases** - enzymes that catalyze the joining of two large molecules by forming a new bond, typically accompanied by the hydrolysis of ATP. Understanding these classifications is crucial for histotechnologists and others in the biomedical field, as it allows for the comprehension of metabolic pathways and the role of specific enzymes in various physiological processes.