This volume contains the proceedings of the International Symposium on Function and Biosynthesis of Lipids held November 1976 at Sierra de la Ventana, Argentina. The conference was organized by the Argentine Biochemical Society and co-sponsored by the International Union of Biochemistry and the Pan American Association of Biochemical Societies. The contributions are organized in four sections, preceded by the opening lecture on the role of dolichol phosphate in glycoprotein biosynthesis delivered by Dr. Luis F. Leloir. The first section, on aspects of lipid involvement in the biogenesis of membranes, covers the biosynthesis of saturated and unsaturated fatty acids, including enzymology, biosynthetic pathways, and regulation and modifications during development, in the fetus and in tumor cells. Papers on the composition and assembly of membrane components, lipid interactions with proteins and enzymes, developmental changes of lipids, and newer approaches to survey the organization and biogenesis of cellular membranes complete this section. New information as well as reviews of current concepts about structural specificity, biosynthesis, and function of glycosphingolipids are included in the second section. The third section is devoted to various aspects of biosynthesis, turnover, and function of lipids in the central nervous system, such as metabolism of polyenoic fatty acids, base-exchange reactions, biosynthesis of complex lipids, and the latest progress in phosphatidylinositol biochemistry. In addition papers on the implications of lipids in transmitter release and in receptors are included. The fourth section is composed of several contributions on essential fatty acids in human nutrition, diet, brain, developing retina, and testes, as well as on enzymological studies.