Comparison of RNA and DNA Polymerases
13 Questions
1 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the role of the 3'OH group in RNA synthesis by RNA polymerase?

  • It acts as a nucleophile attacking the alpha phosphorous of the incoming NTP. (correct)
  • It serves as a template for the addition of the next base.
  • It interacts with the 5' end of the mRNA strand.
  • It coordinates with divalent metals at the active site.

    • How does the initiation of RNA synthesis by RNA polymerase differ from DNA polymerase?

  • RNA polymerase uses Mg2+ ions in the mechanism, while DNA polymerase uses Zn2+ ions.
  • The 5’ to 3’ directionality of RNA synthesis is opposite to that of DNA synthesis.
  • RNA polymerase requires a primer to start synthesis, while DNA polymerase does not. (correct)
  • DNA polymerase initiates transcription at the +1 site of the DNA, while RNA polymerase does not have a specific initiation site.

    • What structural feature of RNA polymerase's active site allows for the correct positioning of the 3'OH group during RNA synthesis?

  • Requirement of primase activity
  • Presence of a 5' cap structure
  • Interaction with divalent metals that coordinate with the phosphates in the NTP (correct)
  • Incorporation of a template strand

    • What is the main difference between DNA and RNA polymerases?

    <p>DNA polymerase has proofreading ability, while RNA polymerase does not.</p> Signup and view all the answers

    What occurs at the active site of RNA polymerase during elongation?

    <p>Nucleoside triphosphates are added to the growing RNA chain.</p> Signup and view all the answers

    Which statement describes the action of RNA polymerase during termination?

    <p>It recognizes a termination signal and dissociates from the DNA.</p> Signup and view all the answers

    In terms of fidelity during synthesis, why are DNA polymerases considered more accurate than RNA polymerases?

    <p>DNA polymerases incorporate fewer incorrect nucleotides into the growing strand.</p> Signup and view all the answers

    What is the role of 3'OH in both RNA and DNA polymerases?

    <p>Acts as a nucleophile</p> Signup and view all the answers

    Why does RNA polymerase have no need for a primer during synthesis?

    <p>Denovo synthesis</p> Signup and view all the answers

    What is the primary reason for DNA polymerase to have a separate site with exonuclease activity?

    <p>Provides correction of incorrectly added bases</p> Signup and view all the answers

    Which enzyme requires NTPs such as ATP, GTP, CTP, and UTP for synthesis?

    <p>RNA Polymerase</p> Signup and view all the answers

    In what way are DNA polymerase and RNA polymerase structurally different despite their similar active sites?

    <p>RNA Polymerase gives rise to a 5'pppXYZ~ product</p> Signup and view all the answers

    What evolutionary concept is consistent with the similarities in the active sites of RNA and DNA polymerases?

    <p>Convergent evolution</p> Signup and view all the answers

    More Like This

    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser