Today in class we reviews the operon system and its relationship with biotechnology. We first took a quiz on protein synthesis and then began to what controlled the production of proteins. The operon system is only present in prokaryote cells or cells without a nucleus. Their are two types of operon systems; induceible and repressive. An example of the repressive operon system is the tryptophan operon system:
At the left end their is the regulatory gene that when translated by the RNA polymerase, produces mRNA which then produces the repressor. As the RNA polymerase continues down the line it reads the genes for tryptophan. As a result, tryptophan is produced until there is enough to activate the repressor. Once activated, the repressor binds to the operator and blocks off the tryptophan gene so that it is no longer produced.
The induceible operon system is different because it switches off an active repressor. An example of an induceible system is the lactose operon system:
As you can see, once lactose is present the repressor is deactivated and un-binds itself from the operator. This allows the RNA polymerase to read the gene and produce whatever that gene dictates.
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