THE FLUID MOSAIC MODEL OF THE STRUCTURE OF CELL MEMBRANES

Abstract

This chapter discusses the fluid mosaic model of the structure of cell membranes. The fluid mosaic model has evolved by a series of stages from earlier versions. Thermodynamic considerations about membranes and membrane components initiated, and are still central to, these developments. The fluid mosaic model is applicable to most biological membranes, such as plasmalemmal and intracellular membranes, including the membranes of different cell organelles, such as mitochondria and chloroplasts. These membranes are referred to as functional membranes. There may be some other membrane-like systems, such as myelin, or the lipoprotein membranes of small animal viruses. This chapter reviews some of the thermodynamics of macromolecular, and particularly membrane, systems in an aqueous environment. It also describes some of the properties of the proteins and lipids of functional membranes, and explores some of the recent and more direct experimental evidence in terms of the model. The fluid mosaic model suggests new ways of thinking about membrane functions and membrane phenomena.