It is always transcribed.
In Figure 84, the correct model showing RNA polymerase, lactose, and repressor protein when the structural genes are being transcribed is model C. This model illustrates the lactose binding to the repressor protein, causing it to dissociate from the operator region, allowing RNA polymerase to transcribe the structural genes.
The lactose operon is likely to be transcribed in the absence of glucose and presence of lactose. When glucose is low and lactose is available, the inducer molecule allolactose binds to the repressor protein, causing it to be released from the operator region and enabling RNA polymerase to transcribe the operon.
A repressor protein binds to the operator region of DNA to inhibit the binding of RNA polymerase, blocking transcription of the gene. This mechanism is common in prokaryotic organisms to regulate gene expression by preventing transcription of specific genes when they are not needed.
When lactose is present, it binds to the repressor protein, causing a conformational change that prevents the repressor from binding to the operator region of the lac operon. As a result, RNA polymerase can transcribe the structural genes of the lac operon, leading to the production of enzymes involved in lactose metabolism.
The portion of a eukaryotic gene that is translated is the coding sequence, which consists of exons. Exons are the segments of DNA that contain the information to be transcribed into mRNA and translated into protein. Introns are non-coding sequences that are removed during RNA processing and do not contribute to the final protein product.
In Figure 84, the correct model showing RNA polymerase, lactose, and repressor protein when the structural genes are being transcribed is model C. This model illustrates the lactose binding to the repressor protein, causing it to dissociate from the operator region, allowing RNA polymerase to transcribe the structural genes.
When tryptophan is absent, the repressor protein is in an inactive state, allowing transcription of the trp operon to continue. This is because the repressor protein needs tryptophan to bind to it, enabling it to attach to the operator region and block transcription of the operon.
a repressor protein
The regulator
When the repressor protein in not functioning then the gene that that protein was blocking will be "turned on". BTW its not right to cheat, even on study guides ;)
The operon segment composed of the gene that codes for a protein repressor is called the regulatory gene. This gene produces the repressor protein that can bind to the operator region of the operon, preventing transcription of the structural genes when the repressor is bound.
The presence of a repressor protein prevents the action of RNA polymerase, which is responsible for transcribing DNA into RNA. By binding to specific regions on DNA, the repressor protein inhibits RNA polymerase from accessing the gene and initiating transcription.
The lactose operon is likely to be transcribed in the absence of glucose and presence of lactose. When glucose is low and lactose is available, the inducer molecule allolactose binds to the repressor protein, causing it to be released from the operator region and enabling RNA polymerase to transcribe the operon.
If Tryptophan is low in the diet, the repressor changes shape and allows the RNA polymerase to attach and copy the DNA so that Tryptophan can be produced by the cell.
A regulator gene encodes for a repressor protein, which can bind to specific DNA sequences to inhibit the expression of target genes. The repressor protein acts as a transcription factor by preventing RNA polymerase from binding to the promoter region of the target gene, thereby regulating its expression.
A repressor protein binds to the operator region of DNA to inhibit the binding of RNA polymerase, blocking transcription of the gene. This mechanism is common in prokaryotic organisms to regulate gene expression by preventing transcription of specific genes when they are not needed.
Repressor