Predict the effect on the inducibility of the lac operon of a mutation that disrupts the function of (a) the crp gene, which encodes the CAP protein, and (b) the CAP-binding site within the promoter.

Video transcript

Hi everyone. Let's take a look at this practice problem together. What is the effect of the inhibition of a dental cyclist activity on the transcription of lack opteron. The lack opteron recall is a set of genes for lactose metabolism of bacteria. So we're looking for how inhibition of a dental cyclists will affect the transcription of it. Will it promote the transcription? Will it slow down the transcription process? Will it prevent the transcription process or will it trigger the overproduction recall that a dental cyclist is an enzyme whenever you see the suffix in biology. A. S. E. That usually means you have an enzyme and the dental cyclists, it was responsible for taking a teepee and converting that into C. A. M. P. Which stands for cyclic adenosine, mono phosphate. So how do a dental cyclists cmp And the lack opteron all work together. Let's take a look at the lack opteron in the lack opteron we've got genes Z. Y. And a an operator a promoter. And this cap site C. A. P. Or CAP stands for catapult light activating protein. Now this is a binding site for cap which is here in purple and that binds to it and helps promote RNA preliminaries to bind to the promoter and thus helps promote transcription. However, cap can only bind here if C A. M. P. Is attached to it. So if a dental cyclist is inhibited it's not going to be making the molecule C. A. M. P. So this won't be able to attach to the cap protein. So you won't have binding of the C. A. P. C. a M. P complex to the cap site. Therefore RNA polymerase won't be able to bind and start transcription. So there will be no transcription occurring. So it's not a promoting transcription process. It's not be slowing down the transcription process and it's not d triggering the overproduction of the LAC operate on. The answer is c. It is preventing the transcription process. Alright, everyone. I hope you found this helpful and I'll see you soon for the next practice problem.