In 1928 he went to Paris to pursue a college education at the Faculte des Sciences of the University of Paris.
Received a Bachelor's degree in natural science in 1931, at which time he obtained a fellowship to work with Edouard Chatton at the University of Strasbourg.
How did the DNA "communicate" with enzymes (biological catalysts) and other structures involved in protein synthesis, all of which were located in the cytoplasm?
It was this mystery that Monod set about solving. Biologists had known for some time that RNA differed from DNA in that it is present both inside the cell nucleus and in the cytoplasm, whereas DNA is only present in the nucleus.
Mahlon Hoagland and Paul Zimmerick of Harvard University had shown that the carrier of amino acids in the cytoplasm during certain chemical reactions was a type of RNA they dubbed "transfer" RNA.
They named this type "DNA-like RNA. "
While this substance was subsequently isolated in other laboratories, its role in the formation, or synthesis, of protein remained a mystery. In the mid-19406 Monod found that the synthesis of an enzyme known as-galactosidase could be prevented by infection by bacteriophage without affecting the actual activity of the enzyme.
This was a curious discovery, and it prompted him to look for the relationship between-galactosidase and the gene which coded for its production.
After several years of research he found that there was a relationship between the activity of the enzyme and protein synthesis. Monod carried out more experiments in this area in 1958 with Francois Jacob and Arthur Pardee.
The results of these experiments and others led Monod and Jacob to proposethe ideas of messenger RNA and the operon.
Their idea was that, through a process resembling the one in which DNA reproduces itself within the nucleus, a kind of RNA is formed from the DNA template that contains an exact copy of the genetic information contained in the DNA.
Upon entering the cytoplasm messenger RNA associates itself with ribosomes, which are small granules composed of ribosomal RNA, essential to protein synthesis.
If the operator is "open, " the genes can generate messenger RNA; when it is "closed, " there is no messenger RNA.
The idea of the operon helped to explain certain important aspects of enzyme synthesis as well as aspects of phage phenomena.
The idea of messenger RNA is extremely important because it explains the previously missing link in how DNA initiates protein synthesis, which is a crucial factor in the ability of cells to function. Jacques Monod received the Louis Rapkine Medal in London in 1958.
He had been married to Odette Bruhl, who died in 1972.