Biological Molecular Machines

Like small molecules taking part in usual chemical reactions, biological molecular machines perform their functions owing to thermal fluctuations and the only difference consists in more complex and specially organized internal dynamics. It is this dynamics that determines processes of free energy transduction in molecular machines. Elements of the statistical theory of mechanochemical and electrochemical coupling are presented and the cases of the actomyosin motor and the proton pump cytochrome bc1 are considered in some detail.