(adenosine triphosphate) a compound that contains adenine, ribose, and three phosphate groups and occurs in cells. The chemical bonds of the phosphate groups store energy needed by the cell, for muscle contraction; this energy is released when ATP is split into ADP or AMP. ATP is formed from ADP or AMP using energy produced by the breakdown of carbohydrates or other food substances. See also mitochondrion.
Subjects: Medicine and health