FERMENT ACTIVE SITE
Active site is a specific region on the surface of a ferment, due to which the ferment expresses its specificity in respect of the substrate. Every ferment is a protein with a unique three-dimensional structure (conformation), which forms an active site. In this active site a certain set of substrates bond with the surface of the ferment. An important feature of the active site structure: the surface of the site is complementary to the surface of the substrate.
They distinguish two zones in an active site: binding site, which is responsible for adjoining of the substrate, and catalytic site, which is responsible for chemical transformation of the substrate. The binding site usually has the form of a deepening, which is formed on the surface of the protein molecule by a certain disposition of amino acids. Composition of the catalytic site of the majority of ferments includes such amino acids, as serine, cysteine, histidine, tyrosine, and lysine. Complex ferments have cofactors or coenzymes in their active sites.
Ferments, which consist of one polypeptide chain, have one active site.