A compound comprising the chemical substances adenine, ribose and phosphates. The chemical bonds of the phosphates contain energy needed for cell METABOLISM that occurs when muscle cells contract. This energy is made available when ATP breaks up to form other chemical groupings – adenosine diphosphate (ADP) and adenosine monophosphate (AMP). The energy needed for recombining AMP and ADP to form ATP is produced by the breakdown of carbohydrates or other constituencies of food.... adenosine triphosphate (atp)
n. a *nucleoside that contains adenine and the sugar ribose and occurs in *ATP. It is also used as an *anti-arrhythmic drug to stop *supraventricular tachycardias and restore a normal heart rhythm. As such, it needs to be injected or infused quickly, which may fleetingly make the patient feel faint and develop chest pain.... adenosine
(ADA deficiency) a genetic disorder affecting about one baby in 25,000 and characterized by a defect in adenosine deaminase (ADA), an enzyme that is involved in purine metabolism. Deficiency of this enzyme results in selective damage to the antibody-producing lymphocytes; this in turn leads to a condition known as *severe combined immune deficiency (SCID), in which the affected baby has no resistance to infection and must be entirely isolated from birth. Such children have only about a 50% chance of surviving for six months. See also gene therapy.... adenosine deaminase deficiency
(IP3) a short-lived biochemical *second messenger formed from *phospholipid in the cell membrane when a chemical messenger (e.g. a hormone or serotonin) binds to receptors on the cell surface. Inositol triphosphate triggers the rapid release of calcium into the cell fluid, which initiates various cellular processes, such as smooth muscle contraction and the release of glucose, histamine, etc. Inositol triphosphate exists for only a few seconds before being converted to inositol by the action of a sequence of enzymes.... inositol triphosphate
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