Unit 1.3 - Control of DNA Expression

Cards (34)

  • What is gene expression?
    Gene expression is the activation of certain genes in a cell to produce particular proteins. Only a fraction of the genes in a cell are expressed.
  • RNA is made up of what?
    A single strand of nucleotides.
  • RNA nucleotides are made up of what?
    A phosphate group, a ribose sugar and a base.
  • What are the four types of RNA bases?
    Adenine, uracil, guanine, cytosine.
  • What are the 3 types of RNA?
    mRNA, tRNA, rRNA.
  • What does mRNA (messenger) do?
    Carries a copy of the DNA code from the nucleus to the ribosomes.
  • What does tRNA (transfer) do?
    Found in the cytoplasm where it binds to specific amino acids and transports them to the ribosome.
  • What does rRNA (ribosomal) do?
    Forms a complex with protein molecules to make the ribosome.
  • What are the two stages of gene expression?
    Transcription and translation.
  • Where does transcription take place?
    In the nucleus.
  • What enzyme breaks apart the hydrogen bonds and unwinds the double helix shape of DNA during transcription?
    RNA polymerase
  • What does RNA do during transcription?
    Synthesizes a primary transcript of mRNA from using RNA nucleotides by complementary base pairing.
  • What does Uracil pair with?
    Adenine.
  • What is a triplet of bases called?
    Codon
  • What does a codon code for?
    A specific amino acid.
  • What are coding regions called?
    Exons
  • What are non-coding regions called?
    Introns
  • What does RNA splicing form?
    A mature mRNA transcript
  • What happens to the introns in a primary transcript?
    They are removed.
  • What happens to exons during RNA splicing?
    Exons are joined together to form the mature transcript.
  • What are ribosomes composed of?
    Proteins and rRNA
  • Why does tRNA fold?
    Complementary base pairing.
  • What does tRNA do in translation?
    Carries amino acids to the ribosome
  • What do tRNA molecules have on them?
    An anticodon and an amino acid attachment site.
  • What is each anticodon complementary to?
    An mRNA codon.
  • Where does translation begin?
    At the mRNA start codon
  • Where does translation end?
    At a stop codon.
  • What happens when the tRNA anticodon binds with a codon?
    It translates the genetic code into a sequence of amino acids.
  • What bonds join amino acids together?
    Peptide bonds.
  • What is a chain of amino acids called?
    A polypeptide chain
  • What is alternative RNA splicing?
    Process of removing introns and joining exons in different combinations to produce multiple mRNA transcripts from a single gene.
  • Why do polypeptide chains fold?
    To form the three dimensional shape of a protein.
  • What is a phenotype?
    Observable characteristic of an individual
  • What is an organism's phenotype determined by?
    The protein's produced as the result of gene expression and also environmental factors.