Enzyme Classification - Biological Molecules and Enzymes

Enzymes can be classified into Six Categories

1) Oxidoreductases

2) Transferases

3) Hydrolases

4) Lyases

5) Isomerases

6) Ligases

Oxidoreductases

Catalyze the transfer of electrons or hydrogen ions (i.e., oxidation-reduction reactions)

Transferases

Catalyze reactions in which groups are transferred from one location to another

Lyases

Catalyze reactions in which functional groups are added to double bonds, or, conversely, double bonds are formed via the removal of functional groups

Synthase

A particular type of lyase that catalyzes the addition of one substrate to the double bond of a second substrate (ex: ATP synthase)

Isomerases

Catalyze the transfer of groups within a molecule, with the effect of producing isomers

Ligases or Synthetases

Catalyze condensation reactions coupled with the hydrolysis of high energy molecules

Kinases

An enzyme that phosphorylates a molecule

Phosphatases

An enzyme that dephosphorylates a molecule