Enzymes enantiospecific catalysts

Enzymes are natural catalysts par excellence—both in their specificity and the extremely high reaction rates that they achieve. Some enzymes are very specific and accept only one or a limited number of substrates. Others are specific for only a limited part of the substrate structure—as we saw in looking at the digestive enzymes that cleave peptides adjacent to particular residues. The specificity arises from the shape of, and the binding sites in, the active site and from the specificity of the reactions available to the bound substrate. Enantiospecificity arises from the fact that the binding site is composed from amino acids of a particular, consistent chirality and hence provides a chiral environment for the reaction. 

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