Transcriptional regulation of operon gene expression involves ...

Question

Transcriptional regulation of operon gene expression involves the interaction of molecules with one another and of regulatory molecules with segments of DNA. In this context, define and give an example of each of the following:
Positive regulation

Positive regulation

Accepted Answer

Hi, everyone. Let's look at our next question. Besides lactose, which other regulatory molecule helps to increase the transcription of genes of the LAC operon. And our answer choices are AC A MP receptor protein B, Sigma Factor C srn A or DNA D plus. Well, we can recall that the lac operon involves two different types of regulation because the lack gene or the lack metabolism genes only should be expressed in the presence of lactose. So our question is said, besides lactose, so we're not gonna worry about that or in the absence of glucose. So we're looking for the regulatory molecule that's involved in that process where when glucose levels are low, these genes are transcribed. So that involves the molecule of C A MP when glucose levels are low. So glucose drops, C A MP levels rise and C A MP binds to the cap protein C A P, which stands for C A MP receptor protein. Once the C A MP has bound to the cap protein that C A MP cap complex binds to, it's a DNA binding site which in turn optimizes the binding of R N A polymerase to the promoter. So, R N A polymerase will bind to the promoter and transcribe the lac genes as long as the repressor protein has been released. But it does so at a low level. However, when the C A MP cap complex is bound to its binding site, that binding of R N A polymerase to the promoter is enhanced and transcription is turned way up. So the end result of all that is to increase the transcription of the lac operon genes. So a whole lot of steps, let's go back to our answer choices. And we're saying, what is the regulatory molecule among our choices that helps to increase the transcription of these genes? So that's going to lead us right to choice AC A MP receptor protein or cap that's directly involved when it's present. When it has C A MP bound to it, it will cause this whole chain of events that increases that transcription. Let's look at our other answer choices to understand why they're not correct. Choice. B is Sigma factor. This is a subunit of R N A polymerase. It's involved in recognizing and binding to the minus box just upstream of the promoter that allows R N A polymerase to begin transcription. So it's part of beginning transcription, but in a very general way. So the sigma factor is just part of R N A polymerase in any sort of transcription process. So it doesn't specifically increase the transcription of genes. The lack operon. So that's why that's not our answer choice and enjoy C SRN A or small R N A. And these are non coding, small R N A molecules, they are involved in regulatory events. So involved in regulation by binding to M R N A s but not specifically in the lack operon system. So that's why that's not our answer. Choice and then choice N ad plus hopefully recognize that as an electron accept her involved in many processes in the cell. You know, we've talked about that many times in all sorts of biological processes, but it's not directly involved in the lack operon steps, so not our correct answer choice. So again, besides lactose, which other regulatory molecule helps to increase the transcription of genes of the lac operon choice. AC A MP receptor protein. See you in the next video.

Transcriptional regulation of operon gene expression involves the interaction of molecules with one another and of regulatory molecules with segments of DNA. In this context, define and give an example of each of the following:
Positive regulation

Key Concepts

Transcriptional Regulation

Operon

Positive Regulation

Watch next

Transcriptional regulation of operon gene expression involves the interaction of molecules with one another and of regulatory molecules with segments of DNA. In this context, define and give an example of each of the following: Positive regulation

Key Concepts

Transcriptional Regulation

Operon

Positive Regulation

Watch next

Transcriptional regulation of operon gene expression involves the interaction of molecules with one another and of regulatory molecules with segments of DNA. In this context, define and give an example of each of the following:
Positive regulation