Figure 2.

The structure of mitochondrion and the electron transport chain (ETC). The structure of mitochondrion includes a smooth outer mitochondrial membrane (OMM), a folded inner mitochondrial membrane (IMM), an intermembrane space and a central matrix. The ETC, including complexes I-IV, the electron transport ubiquinone and cytochrome c, is responsible for generating ATP and reactive oxygen species (ROS). The ETC produces the electrochemical potential energy contained in the proton (H⁺) gradient inside and outside of the IMM which can help to generate ATP from ADP and Pi by ATP synthase (complex V), as well as generate the mitochondrial membrane potential (ΔΨm).