Mitochondrial ATP synthase catalyzes the formation of adenosine triphosphate (ATP) from adenosine diphosphate (ADP) and inorganic phosphate (Pi) at the expense of the transmembrane electrochemical proton gradient generated by the respiratory electron transport chain. The components of this complex are divided into two separable sectors, F1 and F0. The catalytic F1 sector is located in the matrix and comprises subunits alpha, beta, gamma, delta and epsilon with stoichiometry of 3:3:1:1:1 . Alternating alpha and beta subunits form a hexameric ring that constitute the reactive centers that undergo conformational changes upon rotation of subunit gamma, leading to synthesis of ATP. The catalytic sites are located in the beta subunits. (Adapted from PMID:30888962 and PMID:31418131.)