Energy is usually liberated from the ATP molecule to do work in the cell by a reaction that removes one of the phosphate-oxygen groups, leaving adenosine diphosphate (ADT). When the ATP converts to ADP, the ATP is said to be spent.
ATP contains chemical potential energy that will snuggle up to a metabolic reaction in your cells---like the contraction of muscles or sending electrical messages along your nerve cells---- and release the energy of the bonds that hold the third phosphate molecule to the the rest of the ATP(called ADP) ATP is able to move aroun d in the cytoplasm and deliver the energy to whereever it's needed...likewise it has to pick up this energy from the breakdown of the energy laden nutrients in your food---like glucose, starches, and fats. these large nutrient molcules are unable to move around and interact with energy requiring metabolic processes and transfer their energy---thye need the energy intermediate molecule, the ATP.
