Key features of mitochondrial structure and function of the ETC.
Key structures of the mitochondrion are represented in (A), while (B) depicts the structure of the OXPHOS system and its functioning. Oxidative phosphorylation complexes represent reduced nicotinamide adenine dinucleotide (NADH) dehydrogenase (I), succinate dehydrogenase (II), cytochrome c reductase (III), cytochrome c oxidase (IV) and ATP synthase (V) where Q represents coenzyme Q and cyt c represents cytochrome c. In (B), black arrows show the transfer of electrons between complexes while red arrows show the transfer of protons throughout the chain for the eventual production of ATP and H2O. Features are not to scale.