The hydrolysis of a protein (red) by the nucleophilic attack of water (blue). The uncatalysed half-life is several hundred years.<unk>  is the breakdown of proteins into smaller polypeptides or amino acids. Uncatalysed, the hydrolysis of peptide bonds is extremely slow, taking hundreds of years.<unk>  is typically catalysed by cellular enzymes called proteases, but may also occur by intra-molecular digestion.<unk>  in organisms serves many purposes; for example, digestive enzymes break down proteins in food to provide amino acids for the organism, while proteolytic processing of a polypeptide chain after its synthesis may be necessary for the production of an active protein. It is also important in the regulation of some physiological and cellular processes including apoptosis, as well as preventing the accumulation of unwanted or misfolded proteins in cells. Consequently, abnormality in the regulation of<unk>  can cause disease.<unk>  can also be used an analytical tool for studying proteins in the laboratory, and it may also be used in industry, for example in food processing and stain removal.
Proteolysis
Glucose uptake
Glucuronidation
Glycogenolysis
Glyceroneogenesis
Ethanol metabolism
Catabolysis
Lipid metabolism