User:Marshallsumter/phosphate reaction

Life


Each phosphate reaction that occurs in living cells is a part of phosphate metabolism. These reactions are the basis of life, allowing cells to grow and reproduce, maintain their structures, and respond to their environments. Metabolism is usually divided into two categories: catabolism which yields energy such as the breakdown of food in cellular respiration, and anabolism which uses this energy to construct components of cells such as proteins and nucleic acids.

The KEGG database contains biochemical phosphate reactions, some of which may include a nucleotide such as nucleoside monophosphate (NMP). Various possible phosphate reactions number up to 2371 as of October 20, 2009. Not all of these occur in humans. A list of biochemical phosphate reactions may contain these phosphate reactions. Those that have human genes or have products occurring in humans contribute to human life.

Other inorganic elements such as metals play critical roles in phosphate metabolism, referred to as metal metabolism. Many metal ions act as cofactors for a reaction. Some reactions occur as components of multiple pathways.

Phosphorylation
The addition of a phosphate (PO4) group to another molecule, including any protein, is phosphorylation. It is a form of phosphate anabolism in which the number of phosphates changes from zero to n, where n = 1, 2, 3, or more. Many enzymes and receptors are switched "on" or "off" by phosphorylation.

Phosphorylation is catalyzed by specific protein kinases. A phosphorylase is an enzyme that introduces a phosphate group into an organic molecule.

Dephosphorylation is catalyzed by phosphatases.

Phosphorylation of any amino acid having a free hydroxyl group on a given protein can change the function, association, or localization of that protein.

Phosphorylation of sugars allows cells to accumulate sugars because the phosphate group prevents the molecules from diffusing back across their transporter.