Growth of the Concept of the Paucimolecular Membrane

Abstract

The concept of the paucimolecular membrane derived in the first place from studies, such as those of Gorter and Grendel, on the amount of fatty material that could be extracted from the cell, based on the assumption that this was mainly concentrated at its surface. These studies, and other ones, led to the concept of the bimolecular leaflet of lipid as the fundamental basis of membrane structure. Various considerations demanded, also, the presenee of protein as an intimate part of the structure. The simple structure put forward can account for many of the features of cell permeability, but, where facilitated diffusion is concerned, we must invoke the presence of specialized regions, perhaps pores, that have specific structures into which favored molecules and ionis are able to fit. If this is true, variations in the gross analysis of cell membraines are unlikely to be correlated with gross variations in permeability characteristics; instead we must seek, by indirect methods, to lay bare the chemical features of these specialized regions, which doubtless share many of the characteristics of enzymes.