Microbiology 351 Exam 1 Flashcards - Set 20

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  1. Transcription is prevented when _____ bind to a regulatory sequence, and stimulated when ____ bind to a regulatory sequence.
    A) repressors; activators
    B) repressors; inducers
    C) regulators; repressors
    D) inducers; corepressors
    E) activators; repressors
    A) repressors; activators
    (this multiple choice question has been scrambled)
  2. Which of the following can be used to control sigma factors?
    a) Porteolysis
    b) Anti-sigma factors
    c) Anti-anti-sigma factors
    d) Two of the above
    e) All of the above
    e) All of the above
  3. Error-proof repair pathways include all the following EXCEPT
    A) Nonhomologous end joining
    B) Nucleotide excision repair
    C) Photoreactivation
    D) Base excision repair
    A) Nonhomologous end joining
    (this multiple choice question has been scrambled)
  4. Transcription initiation of the lac operon is enhanced when _____ interacts with RNA polymerase.
    A) glucose
    B) LacI protein
    C) lactose
    D) allactose
    E) cAMP receptor protein
    E) cAMP receptor protein
    (this multiple choice question has been scrambled)
  5. Attenuation is a common regulatory strategy used to control the transcription of operons that code for
    A) Amino acid degredation
    B) Amino acid biosynthesis
    C) Carbohydrate biosynthesis
    D) Carbohydrate degradation
    B) Amino acid biosynthesis
    (this multiple choice question has been scrambled)
  6. In , French scientists Jacques Mnod and Fancois Jacob proposed the revolutionary idea that...
    genes could be regulated
  7. ______ induces expression of the LacZYA operon
  8. Lac operon in the absence of lactose:
    - _____ binds as a tetramer to the operator region
      - it ______ the lac operon by _______ open complex formation by RNA polymerase
    • - LacI
    • - represses, preventing
  9. Lac operon in the presence of lactose:
    - _______ (_____), when at low levels, cleaves and rearranges lactose to make the inducer allolactose
        - Allolactose binds to LacI, _____ its affinity to th eoperator and thus ____ induction of the operon
    • - β-galactosidase (LacZ)
    • - reducing, allowing
  10. Maximum expression of the lac operon requires the presence of ______ and ____ ____ ____ (CRP)
    cAMP, cAMP receptor protein
  11. The cAMP-CRP complex binds to the ______, and interacts with RNA pol to _____ the rate of transcription ______.
    promoter, increase, initiation
  12. In ______ repression, an operon enabling the catabolism of one nutrient is repressed by the presence of a more favorable nutrient (commonly glucose).
  13. Glucose _____ the lac operon.
  14. Glucose transport by the phosphotransferase system causes catabolite repression by inhibiting the ____ permease activity, which is termed _____ _____.
    LacY, inducer exclusion (if lactose cannot enter the cell, the lacZYA operon cannot be induced)
  15. DNA sites that bind regulatory proteins typically exhibit a sequence symmetry that allows unmbiguous recognition. Symmetry usually involves an ______ repeat.
  16. Coupling of transcription and translation can be used to regulate gene expression by _____.

Card Set Information

Microbiology 351 Exam 1 Flashcards - Set 20
2016-03-05 10:41:40
Operon Expression Control
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