KATZIR (Katchalski), AHARON

KATZIR (Katchalski), AHARON (1913–1972), Israeli biochemist and biophysicist. Born in Kiev, Russia, he immigrated to Ereẓ Israel in 1925 with his family, which included his brother Ephraim, who later became the fourth president of the State of Israel (see *Katzir, Ephraim). He studied biology and chemistry at the Hebrew University in Jerusalem and completed his doctorate with honors. To complement his studies in life sciences he also studied mathematics and philosophy and began working at the university as an assistant in the Department of Theoretical Organic and Macromolecular Chemistry. At the invitation of Prof. Chaim *Weizmann he joined the Weizmann Institute of Science in 1948, where he established and chaired the Department of Polymer Research until his death. To strengthen the ties between basic and industrial research he also established the institute's Department of Plastics. In his scientific research Katzir sought to understand the molecular basis of the processes of life. His discoveries in the study of polyelectrolytes led to a new field of study of energy exchange, known as mechanochemistry. The contemporary developments in the field of nanotechnology, such as molecular robots, are based on mechanochemistry. His interest in thermodynamics led him to develop a mathematical approach to exact research on the permeability of biological membranes. His mathematical theory, summarized in his Non-Equilibrium Thermodynamics in Biophysics, was accepted and applied by scientists worldwide. As a result of this research he was awarded the Israel Prize in natural science together with Ora *Kedem in 1961 and many more important prizes. Katzir was instrumental in founding the Israel Academy of Sciences in 1959 and was its vice president from 1960 to 1962 and president from 1962 to 1968. Among his many other activities, he played an active role in founding Ben-Gurion University of the Negev. Katzir was involved in military defense, both as a member of the *Haganah and as one of the founders of Hemed, the scientific corps of the Israel Defense Forces. He was also an extraordinarily gifted lecturer and was considered one of the fathers of popular science in Israel. Over the years he published numerous popular articles and books such as The Crucible of Scientific Revolution (1971), and lectured in nonscientific forums. He was committed to humanity in general and to Israeli society in particular, and was very much involved in day-to-day affairs such as education, community action, and defense. On May 30, 1972, Aharon Katzir was murdered while waiting for his luggage during a terrorist attack at Ben-Gurion Airport.

[Bracha Rager (2^nd ed.)]