Cytochrome c oxidase: some current biochemical and biophysical problems

Few fields of biochemistry have seen such widespread applications of physical theories and techniques as that of biological oxidation. There are obvious reasons for this. Oxidation-reduction reactions form the foundations of bioenergetics, an area which can only be understood in terms of thermodynamic theory. Most components of the mitochondrial respiratory chain contain transition metals, and these elements and their chemical environment can often be studied by modern spectroscopic methods, such as electron-paramagnetic resonance (EPR). The relation between spectroscopic properties and chemical structure of metallo-proteins, e.g. haem proteins, represents one of the few branches of present-day biochemistry to which quantum mechanical calculations can profitably be applied (see, for example, Zerner, Gouterman & Kobayashi, 1966).