This book discusses the ion fluxes and electron transfer processes in biological membranes and artificial bio-films. It provides an in-depth description of the processes at the interface between the membrane/film and substrate electrode. This book takes a comprehensive look at bioenergetics, the energy flow in living systems, discussing ion exchange and electron transfer processes in biological membranes and artificial bio-films, and how these processes contribute to developing modern biosensor and ion-sensor technology, as well as biofuel cells. PrefaceChapter  1. Modeling of Relations between Ionic Fluxes and Membrane Potential in Artificial Membranes.Agata Michalska and Krzysztof MaksymiuChapter 2.  Transmembrane ion fluxes for lowering detection limits of ion-selective electrodes.Tomasz SokalskiChapter  3. Ion transport and (selected) ion channels in biological membranes in health and pathology.Krzysztof DolowyChapter 4. Electrical coupling through gap junctions between electrically excitable cells.Yarra Lefler and Marylka Yoe UusisaariChapter 5. Enzyme-film electrochemistryJulea N. Butt, Andrew J. Gates, Sophie J. Marritt, and David J. RichardsonChapter 6. Plant Photosystem II as an example of a natural photovoltaic deviceWieslaw I. GruszeckiChapter 7. Electrochemical Activation of Cytochrome P450Andrew K. Udit, Michael G. Hill, and Harry B. GrayChapter 8. Molecular Properties and Reaction Mechanism of Multicopper Oxidases Related to their Use in Biofuel CellsEdward I. Solomon, Christian H. Kjaergaard, and David E. HeppnerChapter 9. Electrochemical monitoring of the well-being of cells.Kalle Levon, Qi Zhang, Yanyan Wang, Aabhas Martur, and Ramya KolliChapter 10. Electrochemical Systems Controlled by Enzyme-Based Logic Networks: Towards Biochemicaly Controlled Bioelectronics.Jan Halámek and Evgeny Katz