List of enzymes

This article lists enzymes by their classification in the International Union of Biochemistry and Molecular Biology's Enzyme Commission (EC) numbering system.

Category:Oxidoreductases (EC 1) (Oxidoreductase)Edit

Category:EC 1.1 (act on the CH-OH group of donors)Edit

Category:EC 1.2 (act on the aldehyde or oxo group of donors)Edit

Category:EC 1.3 (act on the CH-CH group of donors)Edit

Category:EC 1.4 (act on the CH-NH2 group of donors)Edit

Category:EC 1.5 (act on CH-NH group of donors)Edit

Category:EC 1.6 (act on NADH or NADPH)Edit

Category:EC 1.7 (act on other nitrogenous compounds as donors)Edit

Category:EC 1.8 (act on a sulfur group of donors)Edit

Category:EC 1.9 (act on a heme group of donors)Edit

Category:EC 1.10 (act on diphenols and related substances as donors)Edit

Category:EC 1.11 (act on peroxide as an acceptor -- peroxidases)Edit

Category:EC 1.12 (act on hydrogen as a donor)Edit

Category:EC 1.13 (act on single donors with incorporation of molecular oxygen)Edit

Category:EC 1.14 (act on paired donors with incorporation of molecular oxygen)Edit

Category:EC 1.15 (act on superoxide radicals as acceptors)Edit

Category:EC 1.16 (oxidize metal ions)Edit

Category:EC 1.17 (act on CH or CH2 groups)Edit

Category:EC 1.18 (act on iron–sulfur proteins as donors)Edit

Category:EC 1.19 (act on reduced flavodoxin as donor)Edit

Category:EC 1.20 (act on phosphorus or arsenic as donors)Edit

Category:EC 1.21 (act on X-H and Y-H to form an X-Y bond)Edit

Category:EC 1.97 (other oxidoreductases)Edit

Category:Transferases (EC 2) (Transferase)Edit

Category:EC 2.1 (transfer one-carbon groups, Methylase)Edit

Category:EC 2.2 (transfer aldehyde or ketone groups)Edit

Category:EC 2.3 (acyltransferases)Edit

Category:EC 2.4 (glycosyltransferases)Edit

Category:EC 2.5

Category:EC 2.5 (transfer alkyl or aryl groups, other than methyl groups)Edit

Category:EC 2.6 (transfer nitrogenous groups)Edit

Category:EC 2.7 (transfer phosphorus-containing groups)Edit

Category:EC 2.8 (transfer sulfur-containing groups)Edit

Category:EC 2.9 (transfer selenium-containing groups)Edit

Category:Hydrolases (EC 3) (Hydrolase)Edit

Category:EC 3.1 (act on ester bonds)Edit

Category:EC 3.2 (act on sugars - glycosylases)Edit

Function and clinical importance of some enzymes in category 3.2.1Edit


Function: Amylase is an enzyme that is responsible for the breaking of the bonds in starches, polysaccharides, and complex carbohydrates to be turned into simple sugars that will be easier to absorb.

Clinical Significance: Amylase also has medical history in the use of Pancreatic Enzyme Replacement Therapy (PERT). One of the components is Sollpura (liprotamase), which help in the breakdown of saccharides into simple sugars.


Function: An enzyme that is produced by animals that forms part of the innate immune system and is abundant in the secretions of saliva, human milk, tears, and mucus. It functions as an antimicrobial agent by splitting the peptidoglycan component of bacterial cell walls, which then leads to cell death.

Clinical Significance: Toxic levels of blood are caused by the excessive production of lysozyme's by cancer cells. Lysozyme's have also been associated with Bronchopulmonary dysplasia (BPD) in newborns and is a key factor in providing the immunology of infants during breast feeding.


Function: Sucrase is a stomachs related protein that mobilizes hydrolysis to convert sucrose into glucose and fructose.

Clinical Significance: Low amounts of Sucrose also known as Sucrose intolerance happens when sucrose isn’t being discharged in the small digestive tract. A result of this is extra gas.


Function: lactase is located in the small digestives system of people and other creatures such as mammals. Lactase is the bases of the total absorption of milk.

Clinical Significance: People who are lactose intolerant have medicine that can help with the digestion. When you are lactose intolerant you might experience gas, bloating, and pain along with other symptoms regarding your digestive system.

Category:EC 3.3 (act on ether bonds)Edit

Category:EC 3.4 (act on peptide bonds - Peptidase)Edit

Category:EC 3.5 (act on carbon–nitrogen bonds, other than peptide bonds)Edit

Category:EC 3.6 (act on acid anhydrides)Edit

Category:EC 3.7 (act on carbon–carbon bonds)Edit

Category:EC 3.8 (act on halide bonds)Edit

Category:EC 3.9 (act on phosphorus–nitrogen bonds)Edit

Category:EC 3.10 (act on sulfur–nitrogen bonds)Edit

Category:EC 3.11 (act on carbon–phosphorus bonds)Edit

Category:EC 3.12 (act on sulfur–sulfur bonds)Edit

Category:EC 3.13 (act on carbon–sulfur bonds)Edit

Category:Lyases (EC 4) (Lyase)Edit

Category:EC 4.1 (carbon–carbon lyases)Edit

Category:EC 4.2 (carbon–oxygen lyases)Edit

Category:EC 4.3 (carbon–nitrogen lyases)Edit

Category:EC 4.4 (carbon–sulfur lyases)Edit

Category:EC 4.5 (carbon–halide lyases)Edit

Category:EC 4.6 (phosphorus–oxygen lyases)Edit

Category:Isomerases (EC 5) (Isomerase)Edit

Category:EC 5.1 (racemases and epimerases)Edit

Category:EC 5.2 (cis-trans-isomerases)Edit

Category:EC 5.3 (intramolecular oxidoreductases)Edit

Category:EC 5.4 (intramolecular transferases -- mutases)Edit

Category:EC 5.5 (intramolecular lyases)Edit

Intramolecular lyases:
EC number Examples
EC Muconate cycloisomerase
EC 3-carboxy-cis,cis-muconate cycloisomerase
EC Tetrahydroxypteridine cycloisomerase
EC Inositol-3-phosphate synthase
EC Carboxy-cis,cis-muconate cyclase
EC Chalcone isomerase
EC Chloromuconate cycloisomerase
EC (+)-bornyl diphosphate synthase
EC Cycloeucalenol cycloisomerase
EC Alpha-pinene-oxide decyclase
EC Dichloromuconate cycloisomerase
EC Copalyl diphosphate synthase
EC Ent-copalyl diphosphate synthase
EC Syn-copalyl-diphosphate synthase
EC Terpentedienyl-diphosphate synthase
EC Halimadienyl-diphosphate synthase
EC (S)-beta-macrocarpene synthase
EC Lycopene epsilon-cyclase
EC Lycopene beta-cyclase
EC Prosolanapyrone-III cycloisomerase
EC 5.5.1.n1 D-ribose pyranase
EC Steroid Delta Isomerase

Category:EC 5.99 (other isomerases)Edit

Category:Ligases (EC 6) (Ligase)Edit

Category:EC 6.1 (form carbon–oxygen bonds)Edit

6-carboxytetrahydropterin synthase

Category:EC 6.2 (form carbon–sulfur bonds)Edit

Category:EC 6.3 (form carbon–nitrogen bonds)Edit

Category:EC 6.4 (form carbon–carbon bonds)Edit

Category:EC 6.5 (form phosphoric ester bonds)Edit

Category:EC 6.6 (form nitrogen–metal bonds)Edit