Adenosine monophosphate (AMP) is a nucleotide that consists of a phosphate group, the sugar ribose, and the nucleobase adenine. It is an ester of phosphoric acid and the nucleoside adenosine. AMP plays an important role in many cellular metabolic processes, being interconverted to ADP and/or ATP, as well as allosterically activating enzymes such as myophosphorylase-b. AMP is also a component in the synthesis of RNA. AMP is present in all known forms of life.

AMP is used as a monomer in RNA. It may also be used to regenerate adenosine triphosphate (ATP) . ATP is a nucleotide that contains a large amount of chemical energy stored in its high-energy phosphate bonds. The energy is used for many metabolic processes. Hence, ATP is considered as the universal energy currency for metabolism. Its functions are for intracellular energy transport for various metabolic processes including biosynthetic reactions, motility, and cell division. AMP may also serve as a source of inosine monophosphate (IMP) . It is sometimes converted into IMP with the catalytic action of myoadenylate deaminase. AMP may also be converted into uric acid that is excreted from the body.

AMP may also occur as a cyclic structure, cyclic AMP that serves as a second messenger for signal transduction at the cellular level. In particular, it is used in transferring into cells the effects of glucagon and adrenaline. These hormones cannot pass through the plasma membrane of target cells and therefore need cAMP as a second messenger. It works by activating protein kinase A, which then phosphorylates other proteins.

In summary, AMP is a nucleotide that plays an important role in many cellular metabolic processes, including intracellular energy transport, biosynthetic reactions, and RNA synthesis. It is also a precursor of ATP and a source of IMP. AMP may occur as a cyclic structure, cyclic AMP, which serves as a second messenger for signal transduction at the cellular level.