Answer:
Electrons in chemical bonds, proton gradient, ATP.
Explanation:
Electrons in a chemical bond have energy to move from one molecule to another, but before they move the energy is stored as potential energy, waiting to be used when is necessary.
Proton gradient also contain energy but stored, since the gradient is just a way to express the concentration from one side or another of a membrane, and is going to change when the concentration of the molecules changes from one side or the other.
ATP is a highly energetic molecule, inside it, it contains the necessary energy to transform another molecules when it releases a phosphorous from it structure.
