Answer:
The reaction that converts a lower-energy molecule into a higher-energy molecule is ADP + P + energy.
Step-by-step explanation:
ATP is the molecule that provides energy to the cell. It possesses three phosphate groups, each of which is bound by high-energy bonds and the separation of a phosphate by hydrolysis of ATP is strongly exergonic. The energy released is used by the cell to perform its functions.
In order to form an ATP molecule, ADP is required to bind to a phosphate group, a process that requires energy to establish the P-O-P bond, so the reaction, which is reversible, would be:
ATP + H₂O ⇄ ADP + Pi + ↑energy
This is what allows to convert a lower-energy molecule into a higher-energy molecule and permits an ATP molecule to become the energy exchanger of living organisms.