This book contains a number of papers dealing with the main topics of a Symposium on "Lipids and Lipid Polymers in Higher Plants", held in July 1976 at the Botanical Institute of the University of Karlsruhe. The symposium was organized by Professors E. Heinz, H.K. Lichtenthaler, H.K. Mangold, and M. Tevini. The sponsorship by the Deutsche Forschungsgemeinschaft and the Erwin-Riesch-Stiftung is gratefully acknowledged. The intention of the Symposium was to bring together in one place scientists working in very different fields of plant lipids, such as fatty acids, glycolipids, phospholipids, prenyllipids, sterols, and lipid polymers. The emphasis was placed on biosynthesis, distribution, function, and physiology of the various higher plant lipids and their role in biomembranes and epidermal cell walls. By combining the major contributions in this book, we hope to give all plant scientists access to the recent developments in biochemistry and physiology of plant lipid metabolism. The editors are very grateful to the contributors, who have taken great care to present up-to-date reviews. Karlsruhe, May 1977 M. TEVINI H.K. LICHTENTHALER Contents Section 1. Function, Organization and Lipid Composition of Biomembranes Chapter 1. Functional Organization of Biomembranes P. SITTE (With 15 Figures) A. Introduction. . . . . 1 B. Membrane Functions . 2 I. Membrane Diversity 2 II. Membranes as Barriers 4 III. Lipids and Permeability . 5 IV. Specific Transport . . . 8 V. Membrane Flow and Membrane Families 9 VI. General Principles of Cellular Compartmentation 10 C. Membrane Biogenesis. . . . . . . . . . . . .