1. Oxidoreductases: Catalyze oxidation-reduction reactions, where electrons are transferred between molecules. These include:
* Dehydrogenases: Remove hydrogen atoms from substrates.
* Oxidases: Use oxygen as an electron acceptor.
* Reductase: Add electrons to substrates.
2. Transferases: Catalyze the transfer of functional groups (like methyl, phosphate, or amino groups) from one molecule to another.
* Kinases: Transfer phosphate groups (phosphorylation).
* Transaminases: Transfer amino groups.
* Glycosyltransferases: Transfer sugar moieties.
3. Hydrolases: Catalyze the cleavage of chemical bonds by adding water.
* Proteases: Break down proteins.
* Lipases: Break down lipids.
* Amylases: Break down carbohydrates.
4. Lyases: Catalyze the breaking of chemical bonds without the addition of water, often creating a double bond.
* Decarboxylases: Remove carbon dioxide from molecules.
* Aldolases: Break down carbohydrates.
5. Isomerases: Catalyze the rearrangement of atoms within a molecule, producing isomers.
* Epimerases: Change the stereochemistry of a chiral center.
* Mutases: Move functional groups within a molecule.
6. Ligases: Catalyze the formation of new bonds between molecules by joining two molecules together, often with the use of ATP (adenosine triphosphate) as an energy source.
* DNA ligases: Join DNA fragments.
* Synthases: Synthesize new molecules.
It's important to note that this is a simplification, and some enzymes may fall into multiple categories. Additionally, there are many sub-classes within each of these categories, reflecting the wide diversity of enzymatic reactions.
