Proton expelled in the intermembrane space returned back to the matrix through complex V (ATP synthase) to generates ATP. ATP synthase (Figure 22.3, B) is a mushroom shaped multimeric protein complex, mainly composed of two proteins Fo and F1. F_o is a membrane bound portion where as F₁ is the complex present into the lumen towards matrix. F_oF₁ complex of mitochondria harvest the proton motive force to catalyze phosphorylation reaction involving ADP and phosphate to generate ATP.
Functions of mitochondria-
1. Production of ATP
2. Generation of Reactive Oxygen Species (ROS) in immune cells to kill infectious agents.
3. Used to track tree of a family.
3. Role in programmed cell death or “apoptosis”