It involves the transfer of the stored chemical energy in food molecules to a form readily usable by organisms. This energy can be used to power those metabolic activities which require energy. This reaction is reversible.
Lactic acid is produced in animals and is associated with muscle fatigue.
In the process with the presence of oxygen, the chemical energy of glucose is released gradually in a series of enzyme-controlled reactions. The energy from ATP is used by organisms to obtain, transform, and transport materials, and to eliminate wastes. Used as an energy source in cellular respiration. Synthesized into other metabolic compounds. These compounds could include proteins, DNA, starch, and fats.