Review of Inducible vs. Repressible Operons

by Jason Amores Sumpter
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in this video, we're going to complete the table that you see down below as we review induce herbal versus repress herbal operas. And so notice that here in this row, with the greenish background, we're focusing on induce herbal operations and then down below in this row with the pinkish background, we're focusing on repress herbal operations and so recall from our previous lesson videos of induce herbal operations that they are normally turned off, which means that they will not be transcribed Normally. However, these induce double operas they can be turned on, and that is why they are called Induce a Bill operas because they can be induced now. The repressor protein is normally going to be active with induce herbal a bronze and of course, the repressor protein is going to repress transcription. And because the repressor protein is normally active, it will be normally repressing transcription to turn off transcription. Normally, however, under the right conditions, when the regulatory molecule is present, specifically, the inducer is present. This little circle right here, the inducer will bind to the repressor protein and inactivate the repressor protein, and so we have here and inactivated repressor protein. The effect of the regulatory molecule. The effect of the inducer is to inactivate the repressor protein, and, of course, in activating the repressor protein is going to allow for transcription to proceed. And so transcription will be on and the induce herbal opera and will be induced. It will be turned on in the presence of a regulatory molecule inducer. And so an example of an induced herbal opera is actually the lack opera, which we're going to talk more details about as we move forward in our course. Now, of course, recall from our previous lesson videos of repress herbal opera is that they are pretty much the exact opposite of induce double operations, and so they're actually normally turned on. Their gene expression is normally on, and so transcription is usually occurring with these repressive all operations. However, under the right conditions, repress herbal operations can be turned off or they can be repressed. And that's why they're called repress herbal opera because they can be turned off or repressed. Now, of course, the repressor protein is normally going to be inactive with an repress herbal opera. And in the inactive state, the repressor protein will not be able to repress transcription. And so transcription will be able to be on, however, in the presence of the regulatory molecule, which in this case is actually going to be a co repressor, this little red circle here, the co repressor will bind to the inactive repressor protein to activate the repressor protein. And so the effect of this regulatory molecule, the effect of the co repressor is to lead to an activated repressor protein. And so notice that the activated repressor protein is now able to bind to the operator and that will repress or block transcription, and so transcription will be turned off. And so notice uh, that an example of a repressive ble opera is going to be the trip opera, which we're going to talk more details about as we move forward in our course. But for now, this year concludes our review of Induce herbal versus repress herbal operations, and we'll be able to get some practice as we move forward. So I'll see you all in our next video