When lactose is absent, the lac operon is typically turned off or repressed. This means that the genes involved in lactose metabolism are not actively transcribed and the production of the necessary enzymes is halted.
The lac operon is shut off when lactose is absent. In the absence of lactose, the repressor protein binds to the operator site, preventing transcription of the lac operon genes.
The lac operon is turned on when lactose is present in the environment and glucose is scarce. This leads to the activation of the lac repressor protein, allowing the expression of genes involved in lactose metabolism. The lac operon is turned off when lactose is absent or glucose is abundant, which prevents the unnecessary expression of these genes.
One clue that the lac operon is on is the presence of lactose in the environment. The lac operon is induced when lactose is available as a substrate for the lac repressor protein, allowing transcription of genes involved in lactose metabolism.
The induction of the lac operon occurs when lactose is present in the environment and glucose is limited. The presence of lactose leads to the activation of the lac repressor protein, allowing RNA polymerase to bind to the promoter region and transcribe the genes involved in lactose metabolism.
The lac operon is not transcribed when both glucose and lactose are present because glucose is the preferred energy source for the cell. When glucose is available, the lac operon is repressed, preventing the cell from wasting energy by metabolizing lactose.
The lac operon is shut off when lactose is absent. In the absence of lactose, the repressor protein binds to the operator site, preventing transcription of the lac operon genes.
The lac operon is turned on when lactose is present in the environment and glucose is scarce. This leads to the activation of the lac repressor protein, allowing the expression of genes involved in lactose metabolism. The lac operon is turned off when lactose is absent or glucose is abundant, which prevents the unnecessary expression of these genes.
its an operon required for the transport and metabolism of lactose.
False. The lac operon is an inducible operon, not a repressible one. It is typically turned off when lactose is absent and activated when lactose is present, allowing the transcription of genes needed for lactose metabolism. In contrast, repressible operons are usually active and can be turned off by the presence of a specific molecule.
The DNA sequence located near the promoter of the lactose operon in E. coli that regulates its expression is called the lac operator. The lac operator binds the lac repressor protein, which inhibits transcription of the operon when lactose is absent. When lactose is present, it binds to the repressor, causing it to release from the operator and allowing transcription to proceed.
One clue that the lac operon is on is the presence of lactose in the environment. The lac operon is induced when lactose is available as a substrate for the lac repressor protein, allowing transcription of genes involved in lactose metabolism.
The induction of the lac operon occurs when lactose is present in the environment and glucose is limited. The presence of lactose leads to the activation of the lac repressor protein, allowing RNA polymerase to bind to the promoter region and transcribe the genes involved in lactose metabolism.
The lac operon is most active when glucose levels are low and lactose is present.
The lac repressor protein has a binding site for lactose itself.
The lac operon is not transcribed when both glucose and lactose are present because glucose is the preferred energy source for the cell. When glucose is available, the lac operon is repressed, preventing the cell from wasting energy by metabolizing lactose.
repressor gene
In the lac operon model, lactose acts as in inducer molecule. In the presence of lactose, the molecule binds to the repressor protein. This repressor-lactose complex is unable to bind to the promoter. When the promoter is not occupied, RNA pol - II binds to it and begins transcribing the structural genes located downstream. Thus, the lac operon is turned on in the presence of lactose.