This book is the first devoted entirely to complex I. It contains chapters written by leaders in the field, covering a wide range of topics from the structure of the complex, properties of its many redox centers, subunit composition, mutagenesis studies, evolution of the enzyme and on to the current understanding of the coupling mechanism and the molecular basis for human pathologies. Features, concise and authoritative review of current state-of-the-art in research on respiratory complex I. The first book, a central enzyme in bioenergetics. Recent breakthroughs in structure elucidation finally allow understanding of the mechanism. Mutations leading to common and severe human disorders are discussed.