Potential energy
ADP cycling supplies the energy needed to do work in a biological system, the thermodynamic process of transferring energy from one source to another. There are two types of energy: potential energy and kinetic energy. Potential energy can be thought of as stored energy, or usable energy that is available to do work. Kinetic energy is the energy of an object as a result of its motion. The significance of ATP is in its ability to store potential energy within the phosphate bonds. The energy stored between these bonds can then be transferred to do work. For example, the transfer of energy from ATP to the protein myosin causes a conformational change when connecting to actin during muscle contraction.