In biochemistry, adenosine triphosphate (commonly called ATP) is the "molecular currency" of intracellular energy transformations. It is a means of storing and transporting chemical energy within the cell, and a precursor for RNA formation. Chemically adenosine triphosphate consists of the adenosine nucleotide (which is ribose sugar and adenine base) plus three other phosphate groups.
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The hydrolysis of the phosphate-phosphate bonds releases energy that can be used by a variety of enzymes, motor proteins, and transport proteins to carry out the work of the cell. This hydrolysis leads to free inorganic phosphate ion and adenosine diphosphate, which can be broken down further to adenosine monophosphate.
In living cells there are also other energetic nucleoside triphosphates like guanine triphosphate. Energy can be easily transfered between them and ATP in reactions like (catalyzed by nucleoside diphosphokinase):