Messenger RNA molecules are very difficult to isolate in bacteria because they are rather quickly degraded in the cell. Can you suggest a reason why this occurs? Eukaryotic mRNAs are more stable and exist longer in the cell than do bacterial mRNAs. Is this an advantage or a disadvantage for a pancreatic cell making large quantities of insulin?

Video transcript

Hi everyone. Let's look at our next problem. It says pre M. R. N. S. And eukaryotic cells undergo three main processing steps, capping at the five prime end. The addition of a poly a tail at the three prime end and splicing to remove introns. Which of the following statements about these steps is or are correct. So we have three statements here that we need to evaluate and see which ones are correct about these processing steps. So statement one says the enzyme cap Em taste catalyze is the production of dye phosphate five prime end. Well, this statement is not correct. Little note down here, Statement one, the enzymes that catalyze the production of the dye phosphate at the five prime end is actually and as I'm called guano will transfer race. So not cap empties, Cap Em taste catalyze is the transfer of a methyl group to D. N. A. Information of the five prime cap. And we can see that Eminem taste. And it's called Cap Em taste. So it's involved in the five prime cap. Um But the cap Em taste catalyze the transfer of a methyl group. Whereas it's the guanciale transfer race that catalyze the production of the dye phosphate at that five prime end. So sentence one is incorrect. So let's look at sentence too, since two says apart from the A A U. A. A signal sequence, the U G U A signal sequence can also direct cleavage and polly ventilation. So polyu ventilation is the process of forming me poly a tail at three prime end. And this statement is true. There are these two alternate signal sequences to direct that cleavage and polly ventilation at the three prime end, and then finally sentenced. Three says the splicing reaction is catalyzed by the splice zone. Well, this is also correct. The spice zone is a large protein complex that recognizes splice sites in the pre M. RNA sequence. So when we look at our answer choices, we know that statements two and three are correct, but one is incorrect and we look at our answer choices. We see that's choice B two and three are correct, but one is incorrect. See you in the next video.