Adenosine diphosphate

Adenosine diphosphate (ADP) is a key intermediate in the body’s energy metabolism—it serves as the base to which energy-producing reactions attach an additional phosphate group, forming adenosine tri-phosphate (ATP). ATP then diffuses throughout the cell to drive reactions that require energy.

The chemical reactions that produce ATP from ADP were discovered by Paul Boyer of the University of California, Los Angeles, and John Walker of the Medical Research Council in the United Kingdom. They received the 1997 Nobel prize in chemistry for their accomplishment.

The reverse reaction, namely the production of ADP from ATP by the removal of a phosphate group, is valuable for living organisms, because the phosphate removal also releases energy. The energy can be used to make cell components or to power reactions that are necessary for cell survival.

Structurally, ADP consists of the purine base adenine (a complex, double-ring molecule containing five nitrogenatoms) attached to the five-carbon sugar ribose; this combination is known as adenosine. Attaching two connected phosphate groups to the ribose produces ADP. Schematically, the structure may be depicted as Ad-Ph-Ph, where Ad is adenosine and Ph is a phosphate group.

See also Metabolism.

Adenosine diphosphate

Adenosine diphosphate (ADP) is a key intermediate in the body's energy metabolism—it serves as the "base" to which energy-producing reactions attach an additional phosphate group, forming adenosine triphosphate (ATP). ATP then diffuses throughout the cell to drive reactions that require energy.

Structurally, ADP consists of the purine base adenine (a complex, double-ring molecule containing five nitrogen atoms ) attached to the five-carbon sugar ribose; this combination is known as adenosine. Attaching two connected phosphate groups to the ribose produces ADP. Schematically, the structure may be depicted as Ad-Ph-Ph, where Ad is adenosine and Ph is a phosphate group.

See also Metabolism.

adenosine diphosphate (ADP) A high-energy phosphoric ester, or nucleotide, of the nucleoside adenosine. It can undergo hydrolysis to adenosine monophosphate and inorganic phosphate, the reaction releasing 34 kJ/mol of energy at pH 7.

adenosine diphosphate (ADP) High-energy phosphoric ester (i.e. nucleotide) of the nucleoside adenosine. It can undergo hydrolysis to adenosine monophosphate and inorganic phosphate, the reaction releasing 34kJ/mol of energy at pH 7.

adenosine diphosphate (ADP) See ATP.