Answer:
Cellular respiration: It is the process that releases energy by break down of food molecules in the presence of oxygen. Cellular respiration is the process where organisms combine the food molecules with oxygen, diverting chemical energy into these substances and discarding carbon dioxide and water.
Adenosine triphosphate (ATP) molecule which is present in mitochondria capture the chemical energy which is obtained by breakdown of food and release that energy to fuel other cellular processes. There are three metabolic processes in cellular respiration:
1) Glycolysis: In this process, energy is released during the breakdown of a glucose molecule into two pyruvic acids from fats, proteins, and carbohydrates.
2) Kreb cycle: In this process, most of the energy is captured in this pathway by NAD+ and FAD & later converted to ATP.
3) Oxidative phosphorylation: In this process three molecules of ATP is formed by the transfer of one pair of the electron to oxygen.