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What must happen for transcription of the lac operon genes to take place?
Wiki User
∙ 9y ago
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.
Wiki User
∙ 9y ago
Wiki User
∙ 9y agoThe repressor protein falls off the DNA molecule, and RNA polymerase binds to the promoter. ?
Wiki User
∙ 10y agoThe question is incomplete. No options are given (for which of the following) to answer the question.
Wiki User
∙ 9y agoThere must be no glucose present and only lactose.
Wiki User
∙ 11y agomust not occupy promoter
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Where on the lac operon does transcription take place?
The lac operon encodes enzymes required in the digestion and transport of lactose. Transcription is activated when there is lactose in the cellular environment, and RNA polymerase binds to the promoter region of the operon, and activates the expression of lacA, lacZ and lacY.
What three adjacent structural genes does the Iac operon consist of?
The lac operon which facilitates or enables lactose digestion to take place has three adjacent structural genes. These genes include lacZ, lacY and lacA. They all have their own unique purpose.
What is lac operon in E. coli?
The lac operon is a place on the DNA that binds to the DNA to stop the production of the RNA sequence to code for lactase (breaks down lactose) or binds to lactase to let the production of the RNA sequence to proceed.
Where does transcription take place in the cell?
Transcription takes place in the nucleus.
What is RNA transcription and where does it take place?
RNA transcription is when RNA coverts into DNA, which takes place in the ribosomes.
Where on the lac operon does transcription take place?
The lac operon encodes enzymes required in the digestion and transport of lactose. Transcription is activated when there is lactose in the cellular environment, and RNA polymerase binds to the promoter region of the operon, and activates the expression of lacA, lacZ and lacY.
What are the three components of an operon and there roles?
Holy crud, are you in AP Biology too?Anyway... take the trp operon, for instance. Its components are...Five Structural Genes:These genes contain the genetic code for the five enzymes in the Trp synthesis pathwayOne Promoter:DNA segment where RNA polymerase binds and starts transcriptionOne Operator:DNA segment found between the promoter and structural genes. It determines if transcription will take place. If the operator is turned "on", transcription will occur.
What three adjacent structural genes does the Iac operon consist of?
The lac operon which facilitates or enables lactose digestion to take place has three adjacent structural genes. These genes include lacZ, lacY and lacA. They all have their own unique purpose.
What must happen to the DNA before transcription can take place?
It must unwind and separate for transcription to occur
What is lac operon in E. coli?
The lac operon is a place on the DNA that binds to the DNA to stop the production of the RNA sequence to code for lactase (breaks down lactose) or binds to lactase to let the production of the RNA sequence to proceed.
Where does transcription take place in the cell?
Transcription takes place in the nucleus.
Where in the cell does transcription take place and translation?
Transcription takes place in the nucleus and translation takes place on a ribosome in the cytoplasm.
What is RNA transcription and where does it take place?
RNA transcription is when RNA coverts into DNA, which takes place in the ribosomes.
How is lac operon different from trp operon?
1. in lac operon; gene activity is induced when lactose is present in the medium, whereas in case of trp operon, repression of the gene activity takes place in presence of tryptophan in the medium. 2. lac operon spans about 4-6kb...whereas trp operon spans abut 7kb. 3. lac operon helps in the breakdown of lactose into glucose and galactose, to generate energy( catabolic pathway ) in case of trp operon, it helps in the synthesis of enzymes required for the formation of the amino acid Tryptophan( anabolic pathway ). 4. lac operon is an example of positive regulation ; and trp operon is an example of negative regulation. Trp operon is also regulated by other mechanism called attenuation while no such even occurs in lac operon . .
What is the region where RNA polymerase binds on DNA?
The transcription initiation complex around the TATA box.
What place does transcription take in?
The nucleus.
Which direction does transcription take place?
in DNA transcription occurs from the 5' end to the 3' end
