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lactose metabolizing enzymes need not be made when lactose is not present.
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What is the mechanism by which the presence of glucose inhibits the lac operon?
The mechanism by which the presence of glucose inhibits the arabinose operon is catabolite repression. The lac operon is responsible for the metabolism of glucose.
What must happen for transcription of the lac operon genes to take place?
Lac operon is a set of genes that regulates the digestion of lactose. In absence of lactose in the medium, the repressor protein binds to the operator that inhibit the transcription of structural genes such as beta galactosidase, lactose permease and transacetylase. This makes sure to avoid the enzyme synthesis when there is no need!Conversely, when the lactose present in the medium, an isomer of lactose called allolactose bind to the repressor protein, the conformational change in the repressor let it to detach from repressor hence the RNA polymerase can transcribe the structural gene. Although this may be enough for synthesis of structual gene the system is tightly regulated by a protein called CAP (catabolite activator protein) and glucose.Glucose is a preferred source of energy for cell when this desirable source is present, lactose need not be used as a energy resource. What happens is there will be low level of cAMP when there is high amount of glucose and this keeps CAP inactive.When there is low glucose levels, the cAMP would be higher, that binds to CAP to make it active, which in turn binds to the promoter that enhance the transcription of structural genes.Thus, for efficient transcription lac operon structural genes, lactose must be present where glucose must be absent.
Where and when does lactose metabolism occur in humans?
Digestive System.
Where does Lactose metabolism occur in the human body?
the digestive system
The planet that has the most obvious ring system is?
Saturn!
How can you describe the state of the lac operon system if the level of lactose is low indicating the activity and state of all major enzymes and proteins found in the system?
http://en.wikipedia.org/wiki/Lac_operon
What is the role of lactose in regulating lac operon expression?
When the lac operon controls the expression of proteins in the E.coli cell that can break down lactose into two sugars, glucose and galactose. When lactose is present, it binds to the repressor that typically sits on the lac operon, changing the repressor's conformation such that it can no longer bind to the lac operon. Because of this, RNA polymerase can now transcribe the gene into mRNA, which in turn is translated into the proteins that can break down lactose.
What is the mechanism by which the presence of glucose inhibits the lac operon?
The mechanism by which the presence of glucose inhibits the arabinose operon is catabolite repression. The lac operon is responsible for the metabolism of glucose.
In what organ does lactose intolerance occur?
Lactose Intolerance occurs in the digestive system.
What must happen for transcription of the lac operon genes to take place?
Lac operon is a set of genes that regulates the digestion of lactose. In absence of lactose in the medium, the repressor protein binds to the operator that inhibit the transcription of structural genes such as beta galactosidase, lactose permease and transacetylase. This makes sure to avoid the enzyme synthesis when there is no need!Conversely, when the lactose present in the medium, an isomer of lactose called allolactose bind to the repressor protein, the conformational change in the repressor let it to detach from repressor hence the RNA polymerase can transcribe the structural gene. Although this may be enough for synthesis of structual gene the system is tightly regulated by a protein called CAP (catabolite activator protein) and glucose.Glucose is a preferred source of energy for cell when this desirable source is present, lactose need not be used as a energy resource. What happens is there will be low level of cAMP when there is high amount of glucose and this keeps CAP inactive.When there is low glucose levels, the cAMP would be higher, that binds to CAP to make it active, which in turn binds to the promoter that enhance the transcription of structural genes.Thus, for efficient transcription lac operon structural genes, lactose must be present where glucose must be absent.
When is gene expression blocked in the lac operon system?
The repressor protein blocks the genes from making mRNA.
Where and when does lactose metabolism occur in humans?
Digestive System.
Where and when lactose metabolism occurs in humans?
Digestive System.
What is lactate tolerance?
Lactose intolerance is the inability to metabolize lactose, because of a lack of the required enzyme lactase in the digestive system.
Where does Lactose metabolism occur in the human body?
the digestive system
How do you become lactose intolerance?
Lactose intolerance occurs when the digestive system is no longer able to metabolise the sugars (lactose) found in dairy products through producing insufficient amounts of an enzyme called lactase.
What is the function of lac repressor system in E. coli?
It allows lactose to permeate the cell membrane, and then break bonds with glucose and galactose to use the lactose for food.
