Many enzymes were first named for their function.e.g Lactate dehydrogenase for dehydrogenating Lactate.
Some are named for the type of substrate on which they act
1.Urease hydrolysis urea.
2.Lipase acts on lipids.
3.Phosphatase act on organic phosphate.
Many clinically important enzymes are known by this trivial but important names.
The enzymes commission of the international union of biochemistry proposed a systematic convention for naming enzymes which describe their reaction.
The IUB classified enzymes by placing enzymes in one of the six classes depending on the type of reaction they catalyze and they include-
1.Oxidoreductase which are the group of enzymes that catalyze the transfer of electrons in a reaction.e.g Dehydrogenase,oxidase
2.Transferase- which catalyze group transfer reaction such as Methyl transferase,Amino acyl transferase,transketolase.
3.Hydrolases: This catalyze hydrolysis reaction e.g lipases,esterases,phosphatases,nucleases,and cholinesterases.
4.Lyases- They catalyze addition of groups of bonds to double bonds by removal of groups e.g Carbonic anhydrase, Aspartate Amino lyase,Decarboxylase,Desulphatase
5.Isomerase: Transfer of groups within molecules to yield isomeric forms e.g Epimerase,cis-trans isomerases,transferase,trioxophosphate isomerase.
6.Ligases- They catalyze formation of C-C,C-S,C-N bonds by condensation reaction coupled to ATL cleavage.E.g Pyruvate carboxylases, glutamine synthetase.