Cells use two basic forms of energy: Nucleoside Triphosphate Electrochemical gradient, as created by the concentration gradient of an ion. The basic molecule that is used to power most cell functions is ATP, Adenosine Triphosphate. By hydrolysis of the last phosphate bond, energy is produced, which is then used for cellular functions. All the nucleoside triphosphates are used to some extent as an energy source, with ATP leading, followed by GTP (Guanosine Triphosphate), CTP (Cytidine Triphosphate) and UTP (Uridine-5'-Triphosphate).