D.C. Tosteson – författare

This Volume forms the cornerstone of this series of four books on Membrane Transport in Biology. It includes chapters that address i) the theoretical basis of investigations of transport processes across biological membranes, ii) some of the experimental operations often used by scientists in this field, iii) chemical and biological properties common to most biological membranes, and iv) planar thin lipid bilayers as models for biological membranes. The themes developed in these chapters recur frequently throughout the entire series. Transport of molecules across biological membranes is a special case of diffu­ sion and convection in liquids. The conceptual frame of reference used by investigators in this field derives, in large part, from theories of such processes in homogeneous phases. Examples of the application of such theories to transport across biological membranes are found in Chapters 2 and 4 of this Volume. In Chapter 2, Sten-Knudsen emphasizes a statistical and molecular approach while, in Chapter 4 Sauer makes heavy use of the thermodynamics of irreversi­ ble processes. Taken together, these contributions introduce the reader to the two sets of ideas which have dominated the thinking of scientists working in this field. Theoretical consideration of a more special character are also included in several other Chapters in Volume I. For example, Ussing (Chapter 3) re-works the flux ratio equation which he introduced into the field of transport across biological membranes in 1949.

This Volume forms the cornerstone of this series of four books on Membrane Transport in Biology. It includes chapters that address i) the theoretical basis of investigations of transport processes across biological membranes, ii) some of the experimental operations often used by scientists in this field, iii) chemical and biological properties common to most biological membranes, and iv) planar thin lipid bilayers as models for biological membranes. The themes developed in these chapters recur frequently throughout the entire series. Transport of molecules across biological membranes is a special case of diffu­ sion and convection in liquids. The conceptual frame of reference used by investigators in this field derives, in large part, from theories of such processes in homogeneous phases. Examples of the application of such theories to transport across biological membranes are found in Chapters 2 and 4 of this Volume. In Chapter 2, Sten-Knudsen emphasizes a statistical and molecular approach while, in Chapter 4 Sauer makes heavy use of the thermodynamics of irreversi­ ble processes. Taken together, these contributions introduce the reader to the two sets of ideas which have dominated the thinking of scientists working in this field. Theoretical consideration of a more special character are also included in several other Chapters in Volume I. For example, Ussing (Chapter 3) re-works the flux ratio equation which he introduced into the field of transport across biological membranes in 1949.

This second Volume in the series on Membrane Transport in Biology contains a group of essays on transport across single biological membranes separating the inside and outside of cells or organelles. We have not attempted to include material on all types of plasma and intracellular membranes, but rather have emphasized structures which have been studied relatively thoroughly. Four chapters describe transport of different types of molecules and ions across the plasma membranes of mammalian red cells. Two essays concern the excitable membranes of nerve and muscle cells while the remaining four chapters treat transport across several types of intracellular membranes. Water makes up more than two-thirds of the mass of most living cells. The transport of water between the inside and outside of cells and organelles is important for the function of these structures. As a result of investigations in many laboratories over the past four decades, our picture of the water permea­ bility of the red cell membranes is rather detailed when compared to the water permeability of other biological membranes. In Chapter 1, R. I. Macey describes this picture and also considers the permeability of red cell membranes to non­ electrolytes, including metabolic substrates such as sugars, amino acids, purines and nucleosides.