The physics of cell membranes.

An overview is given of the fundamental physics underlying the self-assembly, molecular organisation and electrical properties of the membranes that envelop living cells. These ultra thin (∼ 6 nm) membranes act as a diffusion barrier between the cell interior (cytoplasm) and the external medium. They consist basically of a bi-molecular film of lipid molecules in which are embedded functional proteins that perform a variety of functions, including energy transduction, signalling, transport of ions (and othermolecules), etc. Some examples are also presented of the fascinating and socially and commercially important applications of membrane biophysics.