Molecular Biology

Most of Jacques Monod’s work was carried out at the Pasteur Institute.

In 1949, he published in the journal Annual Review of Microbiology what is now known as the Monod equation , a model for predicting bacterial growth.

In 1953, he challenged the initial model of bacterial enzymatic adaptation, which he renamed enzymatic induction.

In 1958, the PaJaMo experiment (named for Arthur Pardee, Jacob, and Monod) demonstrated that bacteria synthesize an inhibitor to suppress the production of beta-galactosidase.

Subsequently, while working alongside the rest of the international scientific community to conceptualize the existence of a specific type of RNA with a limited lifespan, Monod and Jacob demonstrated its existence in 1960 and named it messenger RNA .

Their operon model was the first demonstration of a form of genetic regulation in bacteria, revealing how genes are alternately activated and repressed to meet the needs of organisms and explaining how cells carrying the same genes can have different functions.

In 1965, together with Jean-Pierre Changeux and Jeffries Wyman, he proposed the allosteric theory to account for the regulatory capabilities of proteins.

As part of his chair at the Collège de France titled “Molecular Biology” (1967–1973), Jacques Monod addressed various aspects of these discoveries in his lectures. He also spoke at numerous international conferences and symposia. Many seminars were held as part of his chair, led by collaborators such as François Gros , Jean-Pierre Changeux, and Jacques Glowinski.

In his opening lecture at the Collège de France, he began a line of thought that he continued throughout his 1970 lecture series and which would give rise to his essay *Chance and Necessity*, an international bestseller.

Appointed director of the Pasteur Institute in April 1971, he relinquished his chair at the Collège de France in order to devote himself fully to this new role.