Electron carrier protein. The oxidized form of the cytochrome c heme group can accept an electron from the heme group of the cytochrome c1 subunit of cytochrome reductase. Cytochrome c then transfers this electron to the cytochrome oxidase complex, the final protein carrier in the mitochondrial electron-transport chain. Loosely associated with the inner membrane. Binds 1 heme c group covalently per subunit. It is not sure whether methylation is on Lys-80 or Lys-81. There are amides at two of the three positions 5, 10, and 11 and at one of the three positions 68, 69, and 70. Belongs to the cytochrome c family. Life shuttle - Issue 76 of November 2006