The molecular basis of life has been a rapidly growing field of science. There is perhaps no other field where such diverse profiles of scientists, ranging from applied mathematicians and theoretical physicists to experimental biologists and medical doctors (physicians), are compelled to communicate and even to col­ laborate. This diversity makes the exchange of information richer but at the same time more cumbersome. One way to facilitate the exchange of information and to overcome the barriers between the different languages used by physicists, chemists and biologists is to organize a meeting on a subject of common interest. A particularly suitable form of such a meeting for younger scientists is a school at an undergraduate or postgraduate level. This volume contains a collection of lectures presented at the International Summer School in Biophysics, held under the title "Supramolecular Structure and Function" in Dubrovnik, Yugoslavia, in September 1981. The topics discussed at the school were inter- and intramolecular interactions in biological systems, and structure, organization and function of biological macromole­ cules and supramolecular structures. Although not all the lectures could be prepared in a written form on time for publication, we hope that the present volume contains valuable up-to-date information on various aspects of the molecular basis of life. We wish to express our gratitude to the eminent authors and to state that, having received so much valuable assistance from them, we as editors can only attach our names to apologies for any errors that may remain.