answersLogoWhite

0

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.

User Avatar

AnswerBot

7mo ago

What else can I help you with?

Continue Learning about Biology

The lac operon is shut off when what is absent?

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.


What turns the lac operon on and off?

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.


What is a clue that the lac operon is on?

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 does the induction of the lac operon occur?

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.


Why is the lac operon not transcribed when both glucose and lactose are present in the medium?

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.

Related Questions

The lac operon is shut off when what is absent?

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.


What turns the lac operon on and off?

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.


The operon that controls the metabolism of lactose is called the what?

its an operon required for the transport and metabolism of lactose.


True are false the lac operon is a repressible operon?

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.


What is the name of the DNA sequence that is located newr the promoter of the lactose operon and regulates the expression of the operon in E.Coli?

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.


What is a clue that the lac operon is on?

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 does the induction of the lac operon occur?

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.


When is lac operon most active?

The lac operon is most active when glucose levels are low and lactose is present.


How does lactose cause the lac operon to turn on?

The lac repressor protein has a binding site for lactose itself.


Why is the lac operon not transcribed when both glucose and lactose are present in the medium?

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.


What genes is not a part of the lac operon?

repressor gene


What environmental factor causes the lac operon to turn on?

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.