ABSTRACT
Mitochondria consist of two easily identifiable aqueous compartments. The intermembrane compartment comprises the space between the inner surface of the outer mitochondrial membrane and the outer surface of the inner mitochondrial membrane. During the process of movement of metabolites into and out of mitochondria, microcompartmentation has been discerned not only on the inner side of the inner membrane, but also at different locations on the cytosolic side of inner membrane. Much valuable information on the transport of anionic metabolites in mitochondria was initially obtained using the swelling technique. The adenine nucleotide translocase catalyzes exchange between Adenosine diphosphate and Adenosine triphosphate, and, therefore, the transport process accompanies movement of a negative charge. The activity of carnitine-acylcarnitine exchange carrier in mitochondria was initially followed by employing the direct transport assay methods using radioactive carnitines. At least two transporters of mitochondria catalyze exchange of organic metabolites, which results in a net movement of electric charge across the inner membrane.
