This volume continues the discussion of the problems of in vivo and in vitro. The recently solved X-ray structure of the mitochondrial creatine kinase and its molecular biology cellular bioenergetics - the tradition we started in 1994 by publication of the focused issue of Molecular and Cellular are analyzed with respect to its molecular physiology and Biochemistry, volume 133/134 and a book 'Cellular Bio­ functional coupling to the adenine nucleotide translocase, as energetics: role of coupled creatine kinases' edited by V. Saks well as its participation, together with the adenylate kinase and R. Ventura-Clapier and published by Kluwer Publishers, system, in intracellular energy transfer. The results of the Dordrecht -Boston. In the present volume, use of quantitative studies of creatine kinase deficient transgenic mice are methods of studies of organized metabolic systems, such as summarized and analyzed by using mathematical models of mathematical modeling and Metabolic Control Analysis, for the compartmentalized energy transfer, thus combining two investigation of the problems of bioenergetics of the cell is powerful new methods of the research. All these results, described together with presentation of new experimental together with the physiological and NMR data on the cardiac results. The following central problems of the cellular bio­ metabolic and mitochondrial responses to work-load changes energetics are the focus of the discussions: the mechanisms concord to the concept of metabolic networks of energy of regulation of oxidative phosphorylation in the cells in vivo transfer and feedback regulation.