Figure 1.

Bioenergetics scheme of mitochondrial membranes and matrix. The oxidative phosphorylation complexes are located in the inner mitochondrial membrane. The Krebs cycle produces a source of electrons whose redox-potential energy is, in turn, harnessed by the electron transport chain. The complement of ion channels that maintain the ionic gradients that establish the membrane potential ΔΨ_m, includine the Ca²⁺ uniporter, Na⁺/Ca²⁺ exchanger, Na⁺/K⁺ exchanger, adenine nucleotide translocator and proton leak.