ATP synthase is a protein located in the inner membrane of mitochondria, it catalyzes the synthesis of adenosine triphosphate- ATP from adenosine diphosphate- ADP and inorganic phosphate-Pi.
This reaction is driven by protons across the membrane due to the electron transport system.
The main energy source is Glucose which is catabolized by three processes namely glycolysis, tricarboxylic acid cycle or Krebs cycle, and finally oxidative phosphorylation to produce ATP.