Where is the energy stored in adenosine triphosphate (ATP)?

The energy in adenosine triphosphate (ATP) is stored specifically in the phosphate bonds. ATP consists of three phosphate groups, and the bonds that connect these phosphate groups are high-energy bonds. When ATP is hydrolyzed—meaning it loses one of its phosphate groups to become adenosine diphosphate (ADP)—the energy released from breaking these bonds is utilized by cells to perform work, such as muscle contraction, nerve impulse propagation, and the synthesis of macromolecules.

The structure of ATP includes a ribose sugar and a nitrogenous base (adenine), but these parts do not hold the energy required for cellular functions; the energy is inherently linked to the phosphoanhydride bonds between its phosphate groups. This makes ATP a crucial molecule for energy transfer within cells, allowing for efficient energy usage in biological processes.