The lac operon of the model bacterium Escherichia coli was the first operon to be discovered and provides a typical example of operon function. It consists of three adjacent structural genes, a promoter, a terminator, and an operator.
In the operon model, sets of genes operate together to result in the production of a specific protein (enzymes) following the central dogma.
236 Operon model . Enzyme induction.
Removal of the repressor from the operator activates the operon. Thus, the operator controls the activity of the operon as a whole.
Answers. Best Answer: An operator is a segment of DNA which regulates the activity of the structural genes of the operon that it is linked to, by interacting with a specific repressor or activator.
An operator, which is a component of the operon model, is defined as. A). a short portion of DNA where an active repressor binds, which blocks transcription.
In the operon model for an inducible system, a regulatory gene codes for the repressor protein. When the inducer is absent, the repressor binds to the operator and no mRNA is synthesized.
The operon model was proposed by Jacob, Monod, and Wollman based on their genetic and biochemical studies on lactose-requiring mutations of E. coli.
A typical cell will have only about 10 copies of this protein. 3. In the absence of lactose, the repressor protein binds to the operator, preventing transcription from the second promoter.
23.1 - Operon Model - Inducible System.