Genetics: DNA Sequences and Gene Expression
8 Questions
0 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 role does DNA gyrase play in DNA manipulation?

  • It interlocks circular DNA molecules during recombination.
  • It acts as a promoter for gene expression.
  • It introduces negative supercoils into DNA. (correct)
  • It binds to stop codons, terminating translation.

    • Which describes the Pribnow box?

  • Regulatory sequence that binds transcription factors
  • Region of bacterial promoter recognized by RNA polymerase (correct)
  • Sequence of nucleotides that can be translated to give a protein
  • Region of mRNA between the 5' end and the translation start site

    • What is an open reading frame (ORF)?

  • Sequence of bases that can be translated to give a protein (correct)
  • A regulatory sequence inside the promoter region
  • Region of mRNA between the 5' end and the translation start site
  • Original RNA molecule obtained by transcription from a DNA template

    • What happens at the termination stage of translation?

    <p>The polypeptide remains in the P site.</p> Signup and view all the answers

    What is the primary function of housekeeping genes?

    <p>They are needed for essential life functions.</p> Signup and view all the answers

    Which statement describes an enhancer?

    <p>It is a regulatory sequence that binds transcription factors.</p> Signup and view all the answers

    How can catenanes be described?

    <p>Circular DNA molecules that become interlocked during transcription or recombination</p> Signup and view all the answers

    What is a characteristic of a constitutive gene?

    <p>It has promoter sequences very close to consensus.</p> Signup and view all the answers

    Study Notes

    DNA Sequences and Gene Expression

    • Genetic code is used to convert the base sequence in nucleic acids, read in groups of three, into the sequence of a tRNA.
    • Termination occurs when no tRNA exists to bind to a stop codon, causing the tRNA holding the polypeptide to remain in the P site.
    • DNA gyrase is an enzyme that introduces negative supercoils into DNA, and is a member of the type II topoisomerase family.
    • Supercoiling refers to the higher-level coiling of DNA that is already a complementary strand.
    • Catenanes are circular molecules of DNA that can become interlocked during transcription or recombination.

    Gene Structure and Regulation

    • An open reading frame is a sequence of bases (either in DNA or RNA) that can be translated to give a protein.
    • Constitutive genes often have both their -10 and -35 region promoter sequences very close to consensus, which are repressed under rare conditions.
    • Enhancers are regulatory sequences inside, and often far away from, the promoter region that bind transcription factors.
    • The 5'-UTR region of an mRNA is located between the 5' end and the translation start site.
    • Primary transcript is the original RNA molecule obtained by transcription from a DNA template, before any processing or modification has occurred.

    Gene Expression and Regulation

    • Housekeeping genes are genes that are switched on some of the time because they are needed for essential life functions.
    • Pribnow box is a region of bacterial promoter 10 bases back from the start of transcription that is recognized by RNA polymerase.

    True or False

    • A: (F) - There is only one possible model for ordering cell-cycle events, the dependent pathway.

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Description

    This quiz covers the genetic code, termination of gene expression, DNA gyrase, and supercoiling. Learn about the processes involved in converting DNA sequences into polypeptides

    More Like This

    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser