What is ATP? Explain its structure, synthesis and function.

ATP, which stands for adenosine triphosphate, is a biomolecule formed by a purine base (adenine), a sugar molecule (ribose) and three phosphate groups. Its main function is to store energy within the cell. This energy is released through an hydrolysis reaction, catalyzed by an enzyme called ATP hydrolase, in which ATP is decomposed in ADP (adenosin diphosphate) and Pi (phosphate). ATP hydrolysis is an exotermic reaction, releasing energy which is used by the cell. This reaction is reversible by action of the ATP synthase, which synthethizes ATP to store energy. Some examples of metabollic processes producing ATP are photosynthesis and respiration.