Allosteric enzymes are those that have more than one activation centre and to which other substances, called allosterically regulators, bind.
Allosteric regulators can be allosteric inhibitors or allosteric activators. The interaction between an allosteric enzyme and the allosteric inhibitor disallows the binding of the substrate to the enzyme. The interaction between the allosteric enzyme and the allosteric activator allows the binding of the substrate to the enzyme and sometimes increases the affinity of the enzyme for the substrate. This regulatory the phenomenon of the enzyme activity is called all asterism.
