ATP production is known as mitochondria's function and it is used in various areas in different living organisms. While oxidative phosphoryllation or chemiosmosis makes a lot of ATP (38 per cycle), fermentation can be usedd for ATP.
ATP energizes and catalyzes these reactions by splitting into ADP and P which are adenosine diphosphate and phosphate. Phosphate increases the potential energy in various chemical reactions.
A very important function it does is storing energy and transporting them