This volume collects a number of the invited lectures and a few selected contrib­ utions presented at the International Symposium on Structure and Dynamics of Nucleic Acids, Proteins and Membranes held August 31st through September 5th, 1986, in Riva del Garda, Italy. The title of the conference as well as a number of the topics covered represent a continuation of two previous conferences, the first held in 1982 at the University of California in San Diego, and the second in 1984 in Rome at the Accademia dei Lincei. These two earlier conferences have been documented in Structure and Dynamics: Nucleic Acids and Proteins, edited by E. Clementi and R. H. Sarma, Adenine Press, New York, 1983, and Structure and Motion: Membranes, Nucleic Acids and Proteins, edited by E. Clementi, G. Corongiu, M. H. Sarma and R. H. Sarma, Adenine Press, New York, 1985. At this conference in Riva del Garda we were very hesitant to keep the name of the conference the same as the two previous ones. Indeed, a number of topics discussed in this conference were not included in the previous ones and even the emphasis of this gathering is only partly reflected in the conference title. An alternative title would have been Structure and Dynamics of Nucleic Acids, Proteins, and Higher Functions, or, possibly, "higher components" rather than "higher functions.