 |
Jacques MonodNobel Prize in Physiology or Medicine, 1965 jointly with François Jacob and André Lvov
Date of Birth: 09.02.1910
Country:  France |
Content:
- Jacques Monod: Nobel Prize-Winning Biologist and Biochemist
- Research and Discoveries
- Post-War Research and Nobel Prize
- Monod favored the latter explanation.
Jacques Monod: Nobel Prize-Winning Biologist and Biochemist
Early Life and EducationJacques Lucien Monod was born in Paris to Charlotte Todd (MacGregor) Monod, an American of Scottish descent, and Lucien Monod, an artist and intellectual whose ancestors were Swiss Protestant Huguenots. When he was seven, his family moved to Cannes, and throughout his life, Monod identified as a southerner rather than a Parisian.
During his adolescence, Monod attended the Lycée de Cannes, studying under his mentor Dor de la Soucher, a humanities teacher and later founder and curator of the Musée d'Antibes. Upon graduating from the lycée in 1928, Monod enrolled in the Faculty of Sciences at the University of Paris (Sorbonne). He later attributed his career choice to his father's influence, stating, "He had the positivist faith in the simultaneous progress of science and society. And it was to him, a lover of Darwin's books, that I owe my early interest in biology."
However, Monod found that the biology taught at the university was decades behind the frontiers of the field. Motivated to acquire a more fundamental education, he studied microbiology and microbial nutrition under André Lwoff, with whom he formed a lifelong friendship. From Boris Ephrussi, he learned biochemical genetics, and Louis Rapkine instilled in him the importance of a molecular biological approach to unraveling the secrets of the cell.
In 1931, Monod received his bachelor of science degree from the Sorbonne and resolved to continue his studies. The following year, he became an assistant in the laboratory of organic evolution at the Sorbonne. In 1934, he joined the zoology laboratory at the Sorbonne, again as an assistant, and a year later was appointed an assistant professor of zoology.
During the summer, he joined a scientific expedition to Greenland aboard the French sailing ship Pourquoi Pas? Two years later, he planned to embark on a second expedition to Greenland on the same vessel but instead sailed with Ephrussi to the United States, thanks to a grant from the Rockefeller Foundation. Tragically, that summer, the Pourquoi Pas? and all aboard vanished without a trace.
Research and Discoveries
From 1936 to 1937, Monod and Ephrussi studied the genetics of the fruit fly Drosophila melanogaster under Thomas Hunt Morgan at the California Institute of Technology. Monod was impressed by the high quality of research and the freedom with which ideas and results were shared among members of Morgan's department, a stark contrast to the more rigid atmosphere of the Sorbonne.
Upon his return to Paris, Monod worked briefly in Ephrussi's laboratory at the Institute of Physicochemical Biology, continuing his biochemical genetic studies of Drosophila, before resuming his duties at the Sorbonne.
Experimenting with Escherichia coli, Monod discovered that cellular energy was primarily used for biosynthetic processes rather than for the maintenance of cell structures. He observed two different growth curves in E. coli colonies depending on which of two different carbohydrates was provided as their food. Lwoff suggested that Monod had encountered the phenomenon of enzyme adaptation, where one enzyme was initially activated and synthesized while the second was repressed, then vice versa. "From that day in December 1940, the whole of my scientific activity was devoted to the study of enzyme adaptation," Monod later wrote.
The following year, Monod received his doctorate from the Sorbonne, based on his research. However, his laboratory supervisor showed little interest in his work, so Monod continued his experiments at the Pasteur Institute. During this time, he actively participated in the Resistance movement, was arrested by the Gestapo, and escaped. After the liberation of France, he received several military honors.
As a staff officer with General de Lattre de Tassigny, he met American military medical officers who introduced him to the latest scientific literature. Two articles caught his eye, describing experiments conducted in the U.S. during the war. One, by Max Delbrück and Salvador Luria, proposed that bacteria undergo spontaneous genetic mutations. "I think I have never read a scientific paper with such avidity," Monod recalled later, "it was my introduction to bacterial genetics." The other identified deoxyribonucleic acid (DNA) as the agent responsible for the transformation of bacteria. These discoveries would guide Monod's subsequent work on DNA and RNA.
Post-War Research and Nobel Prize
After the liberation of Paris, Monod reunited with his family and briefly returned to the Sorbonne, working alone in the zoology laboratory. In 1945, André Lwoff offered him the position of head of laboratory in the Microbial Physiology Department of the Pasteur Institute, one of the teaching and research units of the National Center for Scientific Research. Over the next two decades, Monod and his colleagues explored the molecular biological aspects of bacterial genetics and the enzymology of bacterial cells. In 1954, he became head of the department of cellular biochemistry.
Monod and other researchers at the Pasteur Institute developed an experimental system to investigate the biochemical genetics of the cell. They discovered a mutant strain of E. coli containing beta-galactosidase, an inducible enzyme activated in the presence of lactose in the growth medium, causing its breakdown into component carbohydrates. Monod's team sought to determine what caused the cell to switch on such an enzyme system. Two theories emerged:
- the enzyme is inhibited by the environment, and its induction (activation) results from the removal of this inhibition;
- the gene is inhibited, and induction results from the deinhibition of the gene directing the synthesis of the specific enzyme.
Monod favored the latter explanation.
Appointed head of the department of cellular biology at the Pasteur Institute in 1953, Monod began working closely with François Jacob. This collaboration, which began in the late 1950s, was described by Francis Crick as "the great partnership." Monod and Jacob postulated and proved the existence of messenger RNA, the RNA molecules that carry genetic information from DNA in the cell nucleus to the cytoplasm. Living cells contain three types of RNA: messenger, transfer (soluble), and ribosomal. Messenger RNA conveys the genetic code to ribosomes in the cytoplasm. Transfer RNA carries amino acids from the cytoplasm to the ribosomes, where all three types of RNA interact to synthesize proteins and enzymes on the cell ribosomes. In
