4 - THE MOLECULAR ORGANIZATION OF BIOLOGICAL MEMBRANES

Abstract

This chapter discusses the molecular organization of biological membranes. There are significant pieces of experimental evidence that cannot be reconciled with either the Davson–Danielli–Robertson or the Benson models as representing the predominant pattern of organization of the lipids and proteins of membranes. However, neither the data presented nor any other results so far obtained are clearly inconsistent with the lipid–globular protein mosaic model. Although direct and unambiguous evidence for the mosaic model has not yet been obtained, its consistency with experiment and its thermodynamic feasibility recommend it for further investigation. The lipid–globular protein mosaic model, therefore, provides a good working hypothesis for the gross organization of a membrane. The lipid–globular protein mosaic model is clearly a gross schematic model intended to convey a very general picture of the predominant interactions and organization of the proteins and lipids of membranes. There are many directions in which it can be diversified and refined, although there is not much experimental basis for such elaboration at the present time.