ATP (adenosine triphosphate) is the molecular unit of energy. ATP is made up of 3 phosphate groups, a five carbon sugar, and adenosine. ATP releases energy when it turns into ADP by going through the process known as the Krebs cycle or citric cycle. When one of the 3 phosphate groups detach, energy is released and the ATP becomes ADP. The ADP later bonds to another phosphate group and becomes ATP again. ATP is present in this stork, which uses ATP to perform glycolysis and other functions.