Thinking about the possible role of lipids

We contemplate the possibility that lipids play a subtler functional role in membranes than that of providing a permeability barrier and a 2-dimensional solvent for proteins. An analysis of the structural properties of lipids, as established by X-ray scattering studies of model systems, suggests a variety of molecular processes involving the structure of the lipid matrix in the functions of membranes. By way of illustration, a hypothetical structural transition is considered, involving nerve membrane lipids and underlying the action potential. The design of an experiment, aimed at testing this hypothesis, is described.