ABSTRACT
Life creates and maintains order, which dees the general tendency of entropy increase and therefore demands energy supplies from the surrounding. In living organisms, endergonic processes are running at the expense of a universal cellular energy currency, which must be continuously regenerated. e enzymatic machinery for this provision can be dened as energy metabolism. In aerobic cells, this is accomplished by means of oxidation-reduction reactions, which are linked to conservation and conversion of the combustion energy to be saved in “energy-rich” molecules, such as adenosine triphosphate (ATP). is molecule functions as a universal energy currency whose breakdown can be coupled to the endergonic reactions of biosynthesis, transport, and motion. e majority (~95%) of the biological energy demand in aerobic cells is supplied by the machinery of oxidative phosphorylation residing in mitochondria. Cells, tissues, and organs with continuously high energy consumption are particularly dependent on mitochondria and also vulnerable from their disorders. is chapter highlights the different aspects of mitochondrial role in energy metabolism needed for cellular function and survival and outlines the optical methods of energy metabolism network studies.
