Figure 1.

Schematic representation of oxidative phosphorylation within the mitochondria. Electrons donated from NADH and FADH₂ pass down the electron transport chain with oxygen being the terminal acceptor at complex IV. This movement of electrons results in a shift of protons across the inner mitochondrial membrane, generating the energy necessary for ATP synthase to produce ATP from ADP. FADH₂, flavin adenine dinucleotide, reduced; NADH, nicotinamide adenine dinucleotide, reduced.