MolBioExam3

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  1. This describes how replication occurs as it moves away 4rm ORI
    ironic/bidirectional
  2. This describes error rate of an enzyme. In the case of DNA Pol (DNAP), this is the chance of an error per base incorporated.
    Fidelity
  3. This describes the pattern of DNA synthesis 4rm a single duplex to create 2 new duplexes.
    Semiconservative
  4. This describes how well an enzyme is able to "hold on to" DNA, that is, turnovers per binding event.
    Processivity
  5. This describes the multiple slow events that regulate binding of DnaA to the E.coli chromosome ORI.
    Kinetic control
  6. This describes the effect of requirement in euk cells of Cdc6 for initiating an ORI and Cdc45 for forming replisome, as Cdc6 is only present during G1 phase and Cdc45 is only present in the S phase.
    Cell cycle control
  7. Relative to the replicative DNAP, this is low for primase and translesion DNAP. (2 answers)
    Processivity / fidelity
  8. There is a major increase in this due to binding of DNAP to the sliding clamp.
    Processivity
  9. TRUE/FALSE. Most bacteriai have multiple ORI per chromosome, while euks only have 1/chromosome.
    FALSE
  10. TRUE/FALSE. A divalent metal ion, not an AA side chain, plays a direct role in catalysis in a DNAP active site.
    TRUE 
  11. Which of the following are mechs used by E. coli DNAPIII (DNA pol III) to ensure proper nucleotide is incorporated. (>1 answer)
    A. 5'-3' exonuclease activity
    B. 3'-5' exonuclease acitivty
    C. Shape recognition (induced fit)
    D. Hemimethylation
    E. Conversion of DnaA-ATP to DnaA-ADP
    • B. 3'-5' exonuclease activity  
    • C. Shape recognition (induced fit)
  12. Irreversibility of DNA polymerization in cell is facilitated by 
    A. 3'->5' exonuclease activity 
    B. Increased entropy that accompanies DNA polymerization
    C. Action of pyrophosphatase to cleave inorganic PP to 2Pi
    D. Cleavage of dNTPs to make inorganic PP
    E. Binding of sliding clamp
    C. Action of pyrophosphatase to cleave inorganic PP to 2Pi
  13. This is an RNA-dependent DNA polymerase.
    Telomerase
  14. What does a primase bind to and what does it do?
    DNA helicase and synthesizes 5' portion of Okazaki fragments.
  15. What does a clamp loader do? does it require ATPase?
    requires ATPase for binding of clamp protein to nascent duplex to increase processivity of the DNAP holoenzyme.
  16. This protects the DNA template of the lagging strand before the initiation of a new Okazaki fragment.
    ss(single-stranded) binding protein
  17. What does DAM Methylase and Helicase have in common?
    These 2 activities are required to occur prior to initiation of replication in E.coli.
  18. what does 3'->5' exonuclease help increase?
    fidelity of some DNAPs
  19. What does 5'->3' exonuclease do ?
    this activity of DNA Pol I degrades primer and other sequences upstream of the site of replication.
  20. What does type II topoisomerase do ?
    this protein uses ATP to release strain up-stream of replication fork.
  21. What is the function of a helicase?
    functions at front of replication fork and uses ATP to break bps.
  22. This multisubunit protein is the replicase in E.coli, functioning w/ a high processivity and fidelity relative to most other DNAPs.
    E. coli DNA pol III
  23. DAM methylation is used to make the parental strand during mismatch repair in which domain system? Euk or Prok?
    prokaryotic
  24. The type of repair is initiated by abasic residues or ss breaks that cannot be fixed by ligase. Lindahl pioneered its description.
    Base excision repair
  25. Who studied Mismatch repair ?
    Modrich (and corrects onn-Watson Crick bps and small insertions / deletions)
  26. What does the Nonohomologous and joining repair do ?
    used by euks to fix dsbreaks when a homologous duplex is lacking / cannot be found.
  27. What does the Translesion DNA pol do ?
    a mutagenic mech for resolving DNA damage encountered during replication
  28. Who studied the Nucleotide Excision Repair and what does it do ?
    • Sancar
    • used to remove 1/more damaged bases that could be the product of alkylation or photodimerization
  29. This is a nonmutagenic mech of repairing DNA lesions during DNA replication.
    Recominational Repair
  30. Which DNAP function in Nucleotide excision repair and base excision repair in E.coli?
    E. coli DNAP pol I
  31. TRUE/FALSE. Branch migration determines amt of DNA exchanged during homologous recombination.
    TRUE
  32. Expansions of these are seen in cancer cells that have acquired a defect in mismatch repair.
    Microsattelite 
Author:
mnvang321
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Card Set:
MolBioExam3
Updated:
2015-12-14 21:20:14
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molbio
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Exam 3
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