What happens to the atp molecule after it has been used to do work?

It loos its terminal phosphate and convert back into ATP.

Explanation:

ATP is also called the energy currency of cells. It contains energy in its high energy terminal phosphate bond. Once the bond is broken the energy gets release which is used in various metabolic reactions.

After losing the terminal phosphate the ATP converts into ADP. This ADP than converts back into ATP during substrate-level phosphorylation during the oxidation of organic compounds or in oxidative phosphorylation. Therefore ATP molecule gets converts into ADP after it gets used.