Designing bacteria, François Jacob
Interviewee: François Jacob. Designing bacteria.
The observation, was that if you look at bacteria growing on glucose, they don't make the enzyme galactosidase. The enzyme galactosidase, the galactose is made of two sugars, glucose and galactose, which are attached together. And the galactosidase cuts out and releases glucose and galactose. Now if you grow your cell on glucose as a carbon source, they don't produce the enzyme. If you grow them on galactose, or derivatives of galactose, they make the enzyme betagalactosidase. Now when you grow them on glucose and switch to lactose, there is a small delay before they produce the enzyme. And the problem of Monod was to understand what happens and when I arrived the theory was that the bacteria produce a molecule even without galactose, and when you add galactose the protein molds on galactose and that's why it becomes an enzyme.
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François Jacob explains why Jacques Monod chose to work with the lactose system.
François Jacob draws out the control mechanism he co-discovered.
Jacques Monod and François Jacob work with how bacteria breaks large sugars into smaller pieces.
François Jacob talks about how enzyme production was viewed at the time they were beginning their experiments.
François Jacob talks about the relationship between DNA, ribosomes, and protein production.
François Jacob talks about Genes control the structure of proteins
Robert Horsch talks about the parasitic nature of agrobacterium and the effect it has on the host plant.
François Jacob talks about bacterial mutants that could not metabolize lactose. Using these mutants, Jacob and Monod figured out how protein production is controlled.
Francis Crick describes RNA and its role and Paul Zamecnick explains protein synthesis.
Walter Gilbert describes how they did the experiment to isolate the lac operon repressor.