Several temperature-sensitive mutant strains of E. coli display t...

Question

Several temperature-sensitive mutant strains of E. coli display the following characteristics. Predict what enzyme or function is being affected by each mutation.Synthesis is very slow.

Accepted Answer

Welcome back. Here's our next problem. It says identify the main role of D. N. A polymerase three. So when we look at DNA polymerase, the first thing we notice is that we're talking about DNA polymerase. When we look over our answer choices, two of them refer to synthesizing RNA. Choice C says it synthesizes RNA and only in synthesizes RNA only in the five prime three prime direction. And choice D. Says it synthesizes RNA only in the three prime five prime direction. So right away we can eliminate choices C. And D. Because we have D. N. A polymerase. We're talking about the synthesis of DNA and we can recall that DNA polymerase is something that synthesizes DNA. Because we look at that name polymerase, it's helping to make a polymer, it's adding bases onto the growing polymer. So we're not a choice as A. And D. It synthesizes DNA only in the five prime three prime direction, or only in three prime to five prime direction. Well, when we have a DNA from race, it only adds nucleotides. So nucleotides only added To the three prime end. So therefore our answer choice here has to be choice A. It synthesizes D. N. A. Only in the five prime to three prime direction because we only add new nucleotides on that three prime end. So building the strand in the five prime three prime direction. So that's why choice B is not correct. Since it has the wrong direction here, You will notice that this is d. n. a polymerase three. So in this case we didn't have to remember the other DNA plum races because all our answer choices involve synthesizing DNA. If your question was phrased a little differently and you have distinguished the role of DNA polymerase three as opposed to two or one. Um We can recall briefly that DNA proliferates one, removes those RNA primers that start um DNA synthesis, it also fills in any gaps that arise. Um While DNA polymerase two functions and editing and proofreading Main mainly in the lagging strand of DNA. So just in case you got asked and had to remember the different functions of the different types of DNA polymerase. But in this case we only remember the size of the D. N. A. And it goes in the five prime 23 prime direction. So choice A. Is our answer here and we'll see you in the next video.

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Several temperature-sensitive mutant strains of E. coli display the following characteristics. Predict what enzyme or function is being affected by each mutation.Synthesis is very slow.

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