Conformational basis of energy transduction in mitochondria
The conformational mechanism of energy transduction which we proposed in 1967 was based on an intuitive evaluation of the significance of large amplitude configurational changes which parallel energized processes in mitochondria [l-3] . By now a considerable body of information has been accumulated about the details of the configurational transitions in the mitochondrion [4-61. Moreover, the theory of structured systems with the capability for conservation of energy by a conformational mechanism is now being developed systematically [7]. This interplay of experiment and theory has made it possible to formulate the conformational hypothesis more explicitly and precisely. The tripartite repeating unit of the cristal membrane is the molecular unit of mitochondrial energy transduction. While in theory each repeating unit is a complete operational unit, in practice we are dealing with two dimensional arrays of repeating units within a membrane continuum and with the cooperative effects intrinsic to such arrays. Each repeating unit contains three basic systems which collectively effectuate the conformational transduction of energy. These systems are (a) the primary energizing system (one of the complexes of the electron transfer chain), (b) the conformational frame system, and (c) the discharge-directing system (the ATPase complex is one such system). The electron transfer process within each complex of the chain leads to a conformational transition [8-lo]. But since the electron transfer system is enclosed within a rigid frame (the conformational frame system [ 7]), the conformational expansion of
Ultrastuctural studies of beef heart mitochondria. I. Effects of adenosine diphosphate on mitochondrial morphology.
Abstract A study of the morphology of isolated beef heart mitochondria in various metabolic states has revealed that adenosine diphosphate alone promotes the formation of a highly condensed morphology which remains unchanged when oxidizable substrates and phosphate are introduced. Oxidation rates are substantially altered and adenosine triphosphate is formed while the mitochondrial morphology stays constant. This observation suggests that the morphological appearance of the inner mitochondrial membrane may depend primarily on osmotic changes created by experimental procedures and metabolism under steady state conditions.
Stoichiometry of Proton Translocation through the Respiratory Chain and Adenosine Triphosphatase Systems of Rat Liver Mitochondria
Stoichiometry of Proton Translocation through the Respiratory Chain and Adenosine Triphosphatase Systems of Rat Liver Mitochondria