With the concept of the unit membrane as a central theme, a number of current problems for the theory of membrane structures are discussed from the point of view of the physical chemist. In view of the wide variety of chemical compositions of membranes, some current opinions of the forces maintaining the integrity of membranes are of limited generality. The thermodynamic status of the membrane is discussed, and it is suggested that the new "small-systems" thermodynamics can be usefully employed as a conceptual basis for discussing fluctuations and "phase-changes" in membranes. Arguments are given to suggest that the lipid interior of membranes is more ordered and "crystalline" than is currently supposed. The role of water in membrane structures remains an enigma.
All Science Journal Classification (ASJC) codes
- Cell Biology
- Plant Science