An electrochemical process is a chemical reaction that either causes or is caused by the movement of electrical current. These processes are a type of oxidation-reduction reaction in which one atom or molecule loses an electron to another atom or molecule. In electrochemical reactions, the atoms or molecules in the reaction are relatively far apart from each other compared to other reactions, forcing the electrons being transferred to travel a greater distance and thereby produce an electrical current. Many natural phenomena are based on electrochemical processes, such as the corrosion of metals, the ability of some sea creatures to generate electrical fields, and the workings of the nervous systems of humans and other animals. They also play an important role in modern technology, most prominently in the storage of electrical power in batteries, and the electrochemical process called electrolysis is important in modern industry. Electrochemical processes naturally occur every day, every moment. The energy necessary for all basic and vital functions is the result of an electrochemical process, as the energy flow in all living systems. Moreover, electrochemistry is currently a fast growing research field, being involved in a plethora of different fields of application, including medicine, environment, food science, and nanotechnology. In particular, electrochemical processes occurring in biological systems are continuously characterized in order to deeply understand mechanisms and regulation of such processes.

Electrolysis is an electrochemical process in which electrical current is used to trigger chemical reactions in a substance containing free ions, called an electrolyte. The electrolyte is either melted or dissolved in a solvent, and two electrodes, called the anode and cathode, are immersed in it. When an electrical potential is applied between the electrodes, electricity begins to flow between them, and each electrode begins attracting ions with the opposite of its own charge. The ions gain or lose electrons to the electrodes, causing oxidation of molecules near the anode and reduction of those near the cathode. Electrolysis is used in many areas of industrial processes, including metallurgy, the production of chemicals such as potassium chlorate and (KClO3) trifluoroacetic acid (C2HF3O2), and the extraction of highly reactive elements that are not found in their elemental form in nature, such as sodium and magnesium. The present book collects recent development both in terms of knowledge and applications. In particular, the first section comprises advanced studies on principal electrochemical processes occurring in cells, with a focus on the mitochondrion, the power station of the cell. The relation of mitochondrial electrochemical processes and some pathologies as cancer and Alzheimer is also discussed. Starting from the dynamics of thylakoid membranes in cyanobacterial, the second section of this book reports some interesting applications of electrochemical processes implemented in biological systems, such as the construction of specific single-molecule junctions, sensors, biosensors, and electrodes.