<P> Adenosine triphosphate (ATP) is a complex organic chemical that participates in many processes . Found in all forms of life, ATP is often referred to as the "molecular unit of currency" of intracellular energy transfer . When consumed in metabolic processes, it converts to either the di - or monophosphates, respectively ADP and AMP . Other processes regenerate ATP such that the human body recycles its own body weight equivalent in ATP each day . It is also a precursor to DNA and RNA . </P> <P> From the perspective of biochemistry, ATP is classified as nucleoside triphosphate, which indicates that it consists of three components, a nucleoside (adenine), the sugar ribose, and the triphosphate . It is used in cells as a coenzyme . </P> <P> In terms of its structure, ATP consists of an adenine attached by the 9 - nitrogen atom to the 1 ′ carbon atom of a sugar (ribose), which in turn is attached at the 5 ′ carbon atom of the sugar to a triphosphate group . In its many reactions related to metabolism, the adenine and sugar groups remain unchanged, but the triphosphate is converted to di - and monophosphate, giving respectively the derivatives ADP and AMP . The three phosphoryl groups are referred to as the alpha (α), beta (β), and, for the terminal phosphate, gamma (γ). </P> <P> In neutral solution, ionized ATP exists mostly as ATP, with a small proportion of ATP . </P>

What chemical group is a key component of atp