Enzymes

A great many biochemical reactions occur continuously inside living cells: the digestion of food and the harvesting of energy from it, and the synthesis of the many molecules required for various cellular functions, are two broad examples. Every one of these reactions is catalysed by special proteins called enzymes. As biocatalysts, enzymes accelerate reaction rates by factors on the order of 10⁵, and they do so with very high specificity -- each enzyme acts on a particular substrate or a narrow range of related substrates -- which is precisely what allows so many different reactions to proceed simultaneously, without interfering with one another, inside the same cell. For example, the enzyme carbonic anhydrase catalyses the interconversion of carbonic acid into water and carbon dioxide; the enzyme sucrase catalyses the hydrol …