Bacterial DNA polymerase I and DNA polymerase III perform diff...

Question

Bacterial DNA polymerase I and DNA polymerase III perform different functions during DNA replication.

If mutation inactivated DNA polymerase I in a strain of E. coli, would the cell be able to replicate its DNA? If so, what kind of abnormalities would you expect to find in the cell?

Accepted Answer

Everyone. Let's take a look at this question together which of the following statements regarding DNA polymerase enzymes is incorrect. Is it answer choice. A? They require the presence of a primer sequence to initiate DNA replication. Answer choice B, most DNA polymerase can momentarily stop and reverse replication to remove an incorrect nucleotide and replace it with the correct nucleotide. Answer choice C they can initiate DNA strand synthesis on their own or answer choice D none of these, let's work this problem out together to try to figure out which of the following statements regarding DNA polymerase enzymes is incorrect. So in order to figure out which of the following statements is incorrect, let's recall some information that we have learned about these DNA prelimerase enzymes. So we have DNA enzymes which we know that they require the presence of a primer to initiate DNA synthesis. And we also know that they and fried DNA to ensure accuracy. And we also know that DNA polymerase enzymes synthesize new DNA strands using template strands and they use these template strands to direct the addition of nucleotides to the daughter strands in a complementary and anti parallel manner. So now that we have written down some information about DNA polymerase enzymes. Let's figure out which of the following answer choices is incorrect answer. Choice. A says that they require the presence of a primer sequence to initiate DNA replication, which we know is a true statement since DNA polymerase requires the presence of a primer sequence to which a new DNA nucleotide can be added by that DNA polymerase enzyme. So that means that answer choice A is a true statement making it an incorrect answer. Answer. Choice B says that most DNA polymerase is can momentarily stop and reverse replication to remove an incorrect nucleotide and replace it with the correct nucleotide which we know that answer. Choice B describes the proof reading of DNA polymerase enzymes in order to ensure accuracy, which is something that most DNA polymerase are capable of. So answer choice B is also a true state making it an incorrect answer. Answer. Choice C says that they can initiate DNA strand synthesis on their own, which we know is not true because they require that presence of a primer to initiate DNA synthesis and they also use template strands. So answer choice C is an incorrect statement about DNA polymerase. So that means that answer choice C they can initiate DNA strand synthesis on their own is the correct answer because it is the only statement here regarding DNA polymerase enzymes that is incorrect because we know that DNA polymerase enzymes require the presence of a primer sequence to initiate DNA replication. And that most DNA polymerase can momentarily stop and reverse replication to remove an incorrect nucleotide and replace it with a correct nucleotide. So that means that answer choices. A B and D are all incorrect and answer choice C they can initiate DNA strands on their own is the only statement here about DNA polymerase enzymes that is incorrect, making it the correct answer. I hope you found this video to be helpful. Thank you and goodbye.

Bacterial DNA polymerase I and DNA polymerase III perform different functions during DNA replication.
If mutation inactivated DNA polymerase I in a strain of E. coli, would the cell be able to replicate its DNA? If so, what kind of abnormalities would you expect to find in the cell?

Key Concepts

DNA Replication

Functions of DNA Polymerases

Mutations and Their Effects

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