Jacques Monod

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This article is about the biologist. For the composer, see Jacques-Louis Monod.
Jacques Monod
Jacques Monod nobel.jpg
Born (1910-02-09)9 February 1910
Paris, France
Died 31 May 1976(1976-05-31) (aged 66)
Cannes, France
Nationality French
Fields Biology, Molecular biology
Known for Lac operon, Allosteric regulation
Notable awards Nobel Prize in Physiology or Medicine (1965)

Jacques Lucien Monod (9 February 1910 – 31 May 1976) was a French biologist who was awarded a Nobel Prize in Physiology or Medicine in 1965, sharing it with François Jacob and Andre Lwoff "for their discoveries concerning genetic control of enzyme and virus synthesis".[1]

Monod (along with François Jacob) is famous for his work on the E. coli lac operon, which encodes proteins necessary for the transport and breakdown of the sugar lactose (lac). From their own work and the work of others, he and Jacob came up with a model for how the levels of some proteins in a cell are controlled. In their model, the manufacture of proteins, such as the ones encoded within the lac (lactose) operon, is prevented when a repressor, encoded by a regulatory gene, binds to its operator, a specific site on the DNA next to the genes encoding the proteins. It is now known that repressor bound to the operator physically blocks RNA polymerase from binding to the promoter, the site where transcription of the adjacent genes begins.

Study of the control of expression of genes in the lac operon provided the first example of a transcriptional regulation system. He also suggested the existence of mRNA molecules that link the information encoded in DNA and proteins. Monod is widely regarded as one of the founders of molecular biology.[2][3] Monod's interest in the lac operon originated from his doctoral dissertation, for which he studied the growth of bacteria in culture media containing two sugars.[4]

Monod was also awarded several other honours and distinctions, among them the Légion d'honneur.

Personal life[edit]

Monod was born in Paris to an American mother from Milwaukee, Charlotte (Sharlie) MacGregor Todd, and a French Huguenot father, Lucien Monod who was a painter and inspired him artistically and intellectually.[5][6] He attended the lycée at Cannes until he was 18.[5] In October 1928 he started his studies in biology at the Sorbonne.[5] During World War II, Monod was active in the French Resistance, eventually becoming the chief of staff of the French Forces of the Interior.[7][8]

Professional life[edit]

In Monod's studies he discovered that the course work was decades behind the current biological science. He learned from other students a little older than himself, rather than from the faculty. "To George Teissier he owes a preference for quantitative descriptions; André Lwoff initiated him into the potentials of microbiology; to Boris Ephrussi he owes the discovery of physiological genetics, and to Louis Rapkine the concept that only chemical and molecular descriptions could provide a complete interpretation of the function of living organisms."[6]

His doctoral work explored the growth of bacteria on mixtures of sugars and documented the sequential utilization of two or more sugars. He coined the term diauxie to denote the frequent observations of two distinct growth phases of bacteria grown on two sugars. He theorized on the growth of bacterial cultures and promoted the chemostat theory as a powerful continuous culture system to investigate bacterial physiology (1949, Ann. Rev. Microbiol., 3:371–394; 1950, Ann. Inst. Pasteur., 79:390–410).

The experimental system ultimately used by Jacob and Monod was a common bacterium, E. coli, but the basic regulatory concept (described in the Lac operon article) that was discovered by Jacob and Monod is fundamental to cellular regulation for all organisms. The key idea is that E. coli does not bother to waste energy making such enzymes if there is no need to metabolize lactose, such as when other sugars like glucose are available. The type of regulation is called negative gene regulation, as the operon is inactivated by a protein complex that is removed in the presence of lactose (regulatory induction).

Monod also made important contributions to the field of enzymology with his proposed theory of allostery in 1965 with Jeffries Wyman (1901-1995) and Jean-Pierre Changeux.[9]

He was also a proponent of the view that life on earth arose by freak chemical accident and was unlikely to be duplicated even in the vast universe. "Man at last knows he is alone in the unfeeling immensity of the universe, out of which he has emerged only by chance. His destiny is nowhere spelled out, nor is his duty. The kingdom above or the darkness below; it is for him to choose", he wrote in 1971.[10] He used the bleak assessment that forms the earlier part of the quote as a springboard to argue for atheism and the absurdity and pointlessness of existence. Monod stated we are merely chemical extras in a majestic but impersonal cosmic drama—an irrelevant, unintended sideshow. His views were in direct opposition to the religious certainties of his ancestor Henri's[11] well-known brothers Frédéric Monod and Adolphe Monod. In 1973 he was one of the signers of the Humanist Manifesto II.[12]

Monod was not only a biologist but also a fine musician and esteemed writer on the philosophy of science. He was a political activist and chief of staff of operations for the Forces Françaises de l'Interieur during World War II. In preparation for the Allied landings, he arranged parachute drops of weapons, railroad bombings, and mail interceptions.

Jacques Monod died of leukemia in 1976 and was buried in the Cimetière du Grand Jas in Cannes on the French Riviera.

Bibliography[edit]

Quotations[edit]

  • "The first scientific postulate is the objectivity of nature: nature does not have any intention or goal."[citation needed]
  • "Anything found to be true of E. coli must also be true of elephants."[13]
  • "The universe is not pregnant with life nor the biosphere with man...Man at last knows that he is alone in the unfeeling immensity of the universe, out of which he emerged only by chance. His destiny is nowhere spelled out, nor is his duty. The kingdom above or the darkness below; it is for him to choose"[14]

References[edit]

  1. ^ "The Nobel Prize in Physiology or Medicine 1965 François Jacob, André Lwoff, Jacques Monod". Nobelprize.org. Retrieved 30 June 2010. 
  2. ^ Ullmann, Agnès (2003). Origins of molecular biology: a tribute to Jacques Monod. ASM Press. p. xiv. ISBN 1-55581-281-3. 
  3. ^ Stanier, R. (1977). "Jacques Monod, 1910-1976". Journal of general microbiology 101 (1): 1–12. PMID 330816.  edit
  4. ^ From enzymatic adaptation to allosteric transitions, Jacques Monad, Nobel Lecture, December 11, 1965
  5. ^ a b c Lwoff, A. M. (1977). "Jacques Lucien Monod. 9 February 1910 -- 31 May 1976". Biographical Memoirs of Fellows of the Royal Society 23: 384–412. doi:10.1098/rsbm.1977.0015.  edit
  6. ^ a b "Jacques Monod – Biography". Nobelprize.org. Retrieved 30 June 2010. 
  7. ^ Caroll, Sean (2013). Brave Genius: A Scientist, a Philosopher, and Their Daring Adventures from the French Resistance to the Nobel Prize. Crown Publishing Group. ISBN 978-0307952332. 
  8. ^ Prial, Frank (1 June 1976). "Jacques Monod, Nobel Biologist, Dies; Thought Existence Is Based on Chance". The New York Times. Retrieved 11 October 2013. 
  9. ^ Monod, J.; Wyman, J.; Changeux, J. P. (1965). "On the Nature of Allosteric Transitions: A Plausible Model". Journal of Molecular Biology 12: 88–118. doi:10.1016/S0022-2836(65)80285-6. PMID 14343300.  edit
  10. ^ Monod, Jacques (1971). Chance and Necessity. New York: Alfred A. Knopf. ISBN 0-394-46615-2. 
  11. ^ fr:Descendance de Jean Monod (1765-1836)
  12. ^ "Humanist Manifesto II". American Humanist Association. Retrieved October 10, 2012. 
  13. ^ Friedmann, Herbert Claus (2004). "From ‘Butyribacterium’ to ‘E. coli’ : An Essay on Unity". Biochemistry Perspectives in Biology and Medicine 47 (1): 47–66. doi:10.1353/pbm.2004.0007. 
  14. ^ Davies, Paul (2010). The Eerie Silence. Boston, New York: Houghton Mifflin Harcourt. p. 25. ISBN 978-0-547-13324-9. 

External links[edit]