How does ATP store energy?

ATP (adenosine triphosphate) stores energy in its high energy phosphate bonds.

ATP consists of an adenosine molecule bonded to three phosphate groups in a row. During cellular respiration, energy in food is converted into chemical energy that can be used by cells. This chemical energy is stored in the pyrophosphate bond, which lies between the last two phosphate groups of ATP. When the cells need energy to do any work, ATP cleaves the third phosphate group, releasing a large amount of energy stored in the bond between the third and second phosphate group. This energy is made available to cells to perform essential tasks.