Chemistry

Since the birth of modern chemistry at the beginning of the 19^th century, Jews have taken a full part in all branches of the science, and the percentage of Jews achieving eminence has been high compared to their number in the general population, as has been true in scientific disciplines generally. Thus around 20% of Nobel Prize laureates in chemistry have been Jews.

Henri *Moissan (1852–1907), a French inorganic chemist, was one of the first Jewish scientists to win a Nobel Prize, awarded in 1906 for his investigation and isolation of the element fluorine and for the electric furnace named after him. Otto *Wallach (1847–1931) characterized 12 different terpenes which were different from one another, in place of the far greater number of products previously thought, and charted their interrelationships and determined their structures, based on rings with six carbon atoms as the basic skeletons. He received the 1910 Nobel Prize for chemistry for "his pioneer work in the field of alicyclic compounds." His work was scientifically important in clarifying a field of natural products, and also (through his students) led to the industrial synthesis of camphor and artificial perfumes. Richard *Willstaetter (1872–1942) showed that chlorophyll, the essential agent for plants to absorb sunlight and carbon dioxide for synthesis, has two components, contains magnesium, is closely analagous to the red pigment of blood, and contains phytol. At a time when enzymes were still considered to be mysterious agents specific to life processes, he emphasized the view that they are chemical substances. Fritz *Haber (1868–1934) synthesized ammonia from hydrogen and nitrogen, which led to its commercial production. George Charles de Hevesy (1885–1966) was a pioneer in the use of radioactive tracers or "labeled atoms," an important tool in chemical and biological research. Together with D. Coster, he discovered a new element, no. 72, which he called hafnium, and added a new field – X-ray fluorescence – as a method of analysis of trace materials in minerals, rocks, and meteorites.

Melvin *Calvin (1912–1997) used carbon-14 isotope as a radioactive tracer to study photosynthesis – the process whereby living plants convert atmospheric carbon dioxide into sugars under the influence of sunlight and chlorophyll. Max Ferdinand *Perutz (1914–2002) started the study of the structure of crystalline proteins by X-ray diffraction. After 30 years this enabled a complete analysis to be made of the positions of all the 2,600 atoms in the myoglobin molecule and the 10,000 atoms in the molecule of hemoglobin, the component of blood which carries oxygen to the body cells. Christian Boehmer *Anfinsen (1916–1995) was awarded the Nobel Prize for chemistry in 1972 (jointly with Stanford Moore and William *Stein ) for proving that the three-dimensional, folded structures of protein chains depends partly on the amino acid sequences which make up protein chains and partly on the physiological milieu (the "thermodynamic hypothesis"). Later he applied the technique of affinity chromatography to protein isolation and purification, which enabled the production of large quantities of interferon and opened the way to advances in anti-viral and anti-cancer therapy. Ilya *Prigogine (1917–2003) and his associates used physical chemical experiments and mathematical modeling to understand the basis of stability in chemical reactions and biological systems. He refined the earlier concept of entropy, a measure of disorder in a system, with the theory of dissipation, that is, the regulated fluctuations which promote stability in the face of irreversible change. His theoretical and mathematical formulation of "dissipative structures" created by irreversible processes led to the award of the Nobel Prize in 1977. Herbert C. *Brown (1912–2004) was awarded the Nobel Prize in chemistry in 1979 for his studies on the application of borohydrides and diborane to organic synthesis, which has had a revolutionary impact on synthetic organic chemistry. He discovered that the simplest compound of boron and hydrogen, diborane, adds with remarkable ease to unsaturated organic molecules to give organoboranes. In addition, his studies of molecular addition compounds contributed to the reacceptance of steric effects as a major factor in chemical behavior. Paul *Berg (1926– ) succeeded in developing a general way to join two DNAs together in vitro, work that led to the emergence of recombinant DNA technology, a major tool for analyzing mammalian gene structure and function. Walter *Gilbert (1932– ), a molecular biologist, made significant contributions in the fields of biophysics, genetic control mechanism, and protein DNA interaction. He worked extensively in the field of the early evolution of genes. Roald *Hoffmann (1937– ) focused on molecular orbital calculations of electronic structures of molecules and theoretical studies of transition states of organic and inorganic reactions.

Aaron *Klug (1926– ) was awarded the Nobel Prize in chemistry in 1982 for his study of the three-dimensional structure of the combinations of nucleic acids and proteins. He developed techniques which enabled the study of both crystalline and non-crystalline material and led to "crystallographic electron microscopy." He demonstrated that a combination of a series of electron micrographs taken at different angles can provide a three-dimensional image of particles, a method which is of use in studying protein complexes and viruses. His work later formed the basis of X-ray CT scanner. His subsequent research was on the structure of DNA and RNA binding proteins which regulate gene expression and in particular on the interaction with the zinc finger family of transcription factors which he discovered.

Herbert Aaron *Hauptman (1917– ), the only mathematician to have received the Nobel Prize in chemistry, developed with physicist Jerome Karle mathematical methods for establishing the structure of complex molecules which could previously only be determined by time-consuming, classical crystallographic techniques of more limited scope and accuracy. Sidney *Altman (1939– ) shared the Nobel Prize in chemistry with Thomas Cech for similar discoveries they made in the 1970s and early 1980s while working independently. They found that in its role as a chemical catalyst, the RNA subunit of RNase P from bacteria can cleave some transcripts of genetic information. Rudolph Arthur *Marcus (1923– ) was awarded the Nobel Prize in chemistry in 1992 for his mathematical analysis of the cause and effect of electrons jumping from one molecule to another. Marcus is also well known for his theory of unimolecular reactions in chemistry, the RRKM theory, which more than 50 years after its development is still the standard theory in the field. It treats the fragmentation of high-energy molecules, as in the atmosphere and in combustion.

George A. *Olah (1922– ) was awarded the Nobel Prize for chemistry in 1994 for his work on carbocations. He and his colleagues showed beyond doubt that stable, positively charged organic hydrocarbons made up of hydrogen and carbon can be created. This work has broad theoretical implications for chemical bonding and organic chemistry and practical applications in hydrocarbon technology. Walter *Kohn (1923– ) developed mathematical models and computational techniques for applying quantum mechanics to chemistry. His density functional theory based on electrons' spatial distribution made it possible to describe the bonding of atoms and thereby to study the structure and function of complex molecules.

Aaron J. *Ciechanover (1947– ) and Avram *Hershko (1937– ) became the first Israeli scientists to win the Nobel Prize, sharing it in 2004 with Irwin *Rose . They discovered the ubiquitin proteolytic system, which is now known to be involved in regulating a broad array of biological processes in health and disease, such as division, differentiation, signal transduction, trafficking, and quality control. A drug based on the general discovery of the ubiquitin system is used for the treatment of multiple myeloma.