Cytochrome Function in Relation to Inner Membrane Structure of Mitochondria

Projecting subunits of an average diameter of 80 A are found on the cristae of mitochondria prepared from the muscle of Ascaris lumbricoides. A spectroscopic examination of the cytochrome content of these mitochondria shows no detectable cytochrome c(1), a, or a(3) and does reveal cytochromes of types c and b. Subunits in the same size range are found in cytochrome c deficient mitochondria of the emergent bee, while the frequency of their occurrence along the cristae is decreased relative to the adult bee. Apparently, the cytochrome content of the respiratory chain is not related to the size of the subunits, but may be related to the frequency of occurrence of the subunits.