The lac operon is turned off and on by repressors.
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.
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.
When the lac repressor binds to the O region, RNA polymerase is prevented from beginning the process of transcription. In effect, the binding of the repressor protein turns the operon "off" by preventing the transcription of its genes. (Prentice Hall Biology Book .....Chapter 12 page 310)
repressor gene
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.
Repressors
explain the regulation of gene expression in lac operon.
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.
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.
its an operon required for the transport and metabolism of lactose.
When the lac repressor binds to the O region, RNA polymerase is prevented from beginning the process of transcription. In effect, the binding of the repressor protein turns the operon "off" by preventing the transcription of its genes. (Prentice Hall Biology Book .....Chapter 12 page 310)
repressor gene
The lac operon is most active when glucose levels are low and lactose is present.
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.
Gene expression is blocked in the lac operon system when the lac repressor binds to the operator in the presence of lactose. This prevents RNA polymerase from transcribing the genes, keeping the system off until lactose is available to derepress the operon.
The lac operon is found in prokaryotes, specifically in bacteria such as Escherichia coli. It is a regulatory system that controls the expression of genes involved in lactose metabolism. Eukaryotic cells do not typically have operons like the lac operon.
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.