The activity of some enzymes depends on their inherent structure, while others need cofactors activity 。 Cofactors can be metal ions, metal coordination compounds (such as VB12 coenzyme) or complex organic compounds. The enzyme system is usually called Holoenzyme The protein left after the removal of cofactors is called apoenzyme protein. According to the type of reaction, it can be divided into six categories. Class I: oxidoreductase, which catalyzes redox reactions. Class II: Transferases, which catalyze the transfer of functional groups. Class III: hydrolase, catalyzing hydrolysis reaction. Class IV: Lyase that catalyzes the elimination reaction and forms double bonds. Class V: isomerase, catalyzing isomerization reaction. Class VI: Ligases, also known as synthetases, catalyze the formation of bonds and break the high-energy phosphate bonds in adenosine triphosphate (ATP) molecules.
