Enzymes are divided into six main classes based on the type of reaction they help in.
Here is a simple explanation:
1. Oxidoreductases
- Help in oxidation and reduction (redox) reactions.
- They transfer hydrogen or electrons from one molecule to another.
- Example: Dehydrogenase, Oxidase.
2. Transferases
- Transfer a chemical group (like a phosphate or amino group) from one molecule to another.
- Example: Kinase, Transaminase.
3. Hydrolases
- Break large molecules into smaller ones by adding water (hydrolysis).
- Important in digestion.
- Example: Amylase, Protease, Lipase.
4. Lyases
- Break or form bonds without using water.
- They may form double bonds or remove groups from molecules.
- Example: Decarboxylase, Aldolase.
5. Isomerases
- Rearrange the structure of a molecule to form an isomer.
- Example: Isomerase, Mutase.
6. Ligases (or Synthetases)
- Join two molecules together using energy from ATP.
- Example: DNA ligase, Aminoacyl-tRNA synthetase.
In short:
- Oxidoreductases – oxidation or reduction
- Transferases – transfer groups
- Hydrolases – break with water
- Lyases – break without water
- Isomerases – rearrange atoms
- Ligases – join molecules
These six classes cover all enzyme-catalyzed reactions in living cells.