First published in 1986, Professor Tonomura's book explains at the molecular level how cells use energy harnessed as adenosine triphosphate to perform the fundamental physiological functions such as muscle contraction and the active transport of cations. In all cases, ATPases enzymes are involved and the detailed reaction mechanisms are carefully described. Young collaborators helped Professor Tonomura to put together the first draft of the book, for he was particularly anxious that the text should be accessible to students who were less familiar with the intricacies of the field than he himself, and should reflect their needs. After his sudden, untimely death, Professor Ebashi and his colleagues at the National Institute of Physiological Sciences, Okazaki, updated and completed the text. The result is a well-written, interesting account of the field and this volume forms a worthy memorial to one of the foremost workers in this area of biochemical research.