This book is based on the International Symposium on Bioenergetics held in Nagoya, Japan in 1986, and summarizes the recent progress in the field of bioenergetics with emphasis on the structure - function relationship in the mitochondrial energy transducing complexes. Part 1 of this book explains the structure and function of oxidative phosphorylation systems, describing recent progress in purification and characterization of the components of the energy transducing system. Part 2 compiles the molecular biological approaches in energy transducing systems, dealing with the organization of the genes for biological components. Part 3 is devoted to the reappraisal of hypotheses on the mechanism of energy transduction, discussing the function of the energy transducing systems on the basis of current information on their structure presented in the previous parts.