Respiration

Respiration the breakdown of molecules, usually glucose, but sometimes fat or protein, in the body with a release of energy.

Glucose, for example, is respired aerobically (with oxygen) in the human body thus -

C6H12O6 \+ 6O2 -> 6H2O + 6CO2 \+ energy

C6H12O6 -> 2C3H6O3 \+ less energy

This energy is often used to turn ADP or AMP into ATP, which is then used as a store of energy.