Skip to main content
Pearson+ LogoPearson+ Logo
Start typing, then use the up and down arrows to select an option from the list.


Learn the toughest concepts covered in biology with step-by-step video tutorials and practice problems by world-class tutors

12. Gene Regulation in Prokaryotes




Play a video:
Was this helpful?
Hi in this video we're gonna be talking about Revo switches. So I kind of think rival switches are kind of the coolest things ever but I don't know maybe after this video you'll agree with me. So what arrival switches, rival switches are M RNA sequences found in the five prime untranslated region is what that stands for. Um And this is just a region that obviously isn't translated into protein but it's still present in the M. R. N. A. And so it's the sequence in the five prime untranslated region and it binds small molecules so chemicals or small um just molecules in general. And this controls gene expression of the M. RNA itself. And so rival switches control the expression of themselves. It controls the expression of that M RNA sequence where the rival switch exists. And so there are two main domains in a right bow switch. There is an app timer and this is the RNA sequence. Remember we're dealing with R. N. A. Is an RNA sequence that binds to the small molecule and then you have an expression platform. So after that is bound a secondary structure forms and this regulates gene expression and the secondary structure forms in this expression platform. So a common structure that will form is called the terminator structure and all of these. I feel like everything in this chapter is called the same thing but it means different depending on which opera or what you're talking about. But for arrival switch, the terminator structure um is a structure formed by binding the small leg in and it terminates the translation. So Revo switches actually have the ability to interfere with transcription. It has the ability to interview with splicing and translation Now it can interfere with transcription because remember we're talking about pro carry optic cells um in this these topics and pro carry out ICC cells transcription and translation occur in the same compartment. And so rival switches, even though they're happening on M. R. N. A. Can actually in the five prime untranslated region it can happen it can affect transcription and translation. So when it stops transcription, rebus uh so transcription termination. So the termination of transcription is controlled through that terminator structure which I talked about before and translation termination is controlled through a termination structure. So the same structure but this one actually will block a ribosome binding site. So it can affect both transcription and translation depending on when and where all these structures are found. So this is what they look like. I think they have a really cool structure. One of the questions I hope that you're asking right now is you're saying okay well this is R. N. A. What are all these letters standing for? Why are there W. S. K. S. Ds wise etcetera? Well you'll notice here any of the red ones I believe um bread and then some of these orange ones. These are actually nucleotides and all of these stand for RNA nucleotides. They stand for different things now I don't know the key off the top of my head but we could say well w would stand for A or U. K. Would stand for T. G. Or you. And all of these are different codes and they stand for different combinations of what nucleotide could be there. But all of these little circles represent some type of nucleotide, even if it's not saying which nucleotide it represents and instead isn't a code. So hopefully you ask that question. Um notice here that this is five prime and three prime. So it goes down like this creates these structures, goes all the way back around jeju and ends up here. So we're going that way right all the way around. Um So robert switches are so cool. Hopefully you think so too. But this is definitely a type of pro cryonic gene regulation um which can stop transcription or translation. So with that let's not move on.

Riboswitches are made up of what type of molecule?


Which of the following processes can riboswitches NOT interfere with?