In the Presence of Lactose

by Jason Amores Sumpter
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So now that we know from our last lesson video that in the absence of lactose, the lack opera is off or inactive in this video, we're going to talk about the lack opera and but in the presence of lactose. And so when lactose is readily available to metabolize in the environment, lactose can actually act as an inducer molecule in the lack operas. And so really, it turns out that a derivative of lactose that's called a low lactose uh, you may or may not be responsible for knowing Allah lactose, uh, but a derivative of lactose, uh, is going to bind and inactivate the repressor protein lack I. And so if black eye is inactivated, then that means that it will not. It cannot bind to the operator. And if it cannot bind to the operator, that means that RNA preliminaries will be allowed to initiate transcription of the lack operas, and so that will turn on the lack opera. And so if we take a look at our image down below notice, we're saying in the presence of lactose, when lactose is readily available to metabolize, then lack I. The repressor protein is going to be inactive. And if it's inactive, that's going to allow for lack operation transcription, turning on the lack opera. And so here, again in the title, were saying that the lack opera uh, we're focusing on the lack opera in the presence of lactose. And so this is our molecule to represent lactose. And so notice over here we have again our lack regulatory gene lack I with its own promoter here and lack I is going to be transcribed and translated into the lack. Repressor, however, notice that in the presence of lactose, a derivative of lactose will be able to bind to the lack of repressor and inactivate the lack repressor. And so notice that the lack repressor here has changed its confirmation. And now it is no longer able to bind to the lack operator and block transcription. And so because the inactive lack repressor cannot bind to the operator, this allows RNA preliminaries to bind to the lack promoter and initiate transcription of these lack Oberon genes like Z lack y and lack a and so, of course, it's going to create an M RNA strand, and the M RNA Strand is going to have a stark code on here for each of the genes within it. And ultimately this M R and A is going to be translated. And when it's translated, it's going to be, uh, converted into these enzymes. And these enzymes will be able to break down lactose and so they can go over here and break down lactose and use lactose as an energy source. And so, ultimately, what we're seeing here is that the lack opera is really only going to be on or active in the presence of lactose when lactose is available. And that allows, uh, the genes to be turned on when they are needed. And so this year concludes our brief introduction to the lack opera in the presence of lactose, and we'll be able to get some practice applying the concepts that we've learned as we move forward in our course. And then we'll also get to talk about how glucose will also impact expression of the lack opera. So we'll talk more about that as we move forward. So I'll see you all in our next video