Adenine combines with the sugar ribose to form adenosine, which in turn can be bonded with from one to three phosphoric acid units, yielding the three nucleotidesadenosine monophosphate, adenosine diphosphate, and adenosine triphosphate . Adenine is one of four nitrogenous bases utilized in the synthesis of nucleic acids . A modified form of adenosine monophosphate is thought to be a secondary messenger in the propagation of many hormonal stimuli. Adenosine triphosphate is used in cellular metabolism as one of the basic methods of transferring chemical energy between chemical reactions. Adenosine monophosphate; a mononucleotide found in animal cells and reversibly convertible to ADP and ATP.

Adenosine 5'-triphosphate (ATP) is a multifunctional nucleotide that is most important as a 'molecular currency' of intracellular energy transfer.[1] In this role, ATP transports chemical energy within cells for metabolism. It is produced as an energy source during the processes of photosynthesis and cellular respiration and consumed by many enzymes and a multitude of cellular processes including biosynthetic reactions, motility and cell division. In signal transduction pathways, ATP is used as a substrate by kinases that phosphorylate proteins and lipids, as well as by adenylate cyclase, which uses ATP to produce the second messenger molecule cyclic AMP.