Enzyme Catalysis

A biological substance known as a "enzyme" increases the pace of a process through enzyme catalysis. Since most of these activities involve chemical reactions, most enzymes are proteins. The active site is a specific location inside the enzyme where catalysis typically takes place. Proteins make up the majority of enzymes, either in the form of a single protein chain or several chains working together as a multi-subunit complex. In addition to proteins, enzymes frequently contain non-protein components like metal ions or specialised chemical molecules known as cofactors (e.g. adenosine triphosphate). Numerous cofactors are vitamins, and their function as vitamins is exemplified by their employment in the catalysis of metabolic biological processes. Since many, though not all, metabolically necessary reactions have very low rates when uncatalyzed, it is crucial that biochemical reactions in the cell are catalyzed. Although only the most essential enzymes operate near catalytic efficiency limits and many enzymes are far from optimal, the optimization of such catalytic activities is a major force in protein evolution. General acid-base catalysis, orbital steering, entropic restriction, orientation effects (such as lock-and-key catalysis), motional effects involving protein dynamics, as well as other factors are significant in enzyme catalysis.