Oxidative Phosphorylation, ATP Synthesis, and Other Aspects of Mitochondrial Physiology

Abstract

Living cells require a continual supply of energy to perform the work they must do in order to survive, to grow, and to reproduce. Lipmann (1941) in his general theory of energy transfer emphasized the key role of ATP in work performance (Fig. 15.1). It was then widely believed that the universal role of ATP in biological work performance lies in its possession of two high-energy phosphate bonds. Subsequent discoveries, discussed in Section 5.2.2 and Chapter 10, left doubt that the phosphate bonds in ATP really are endowed with a package of energy higher than that of other phosphate bonds. Alternative sources of energy in the form of ion gradients were suggested (see Jangendorf and Uribe, 1966), which eventually led to the chemiosmotic hypothesis, to be discussed in Section 15.3.3.