Bio1151b Chapter 17 From Gene to Protein
  1. A major function of DNA is to direct the synthesis of           in two steps:                and              .
  2. In prokaryotes, transcription and translation take place simultaneously. In eukaryotes, an intermediate step of RNA             is needed due to the presence of the          .
  3. Transcription has three stages: initiation, elongation. and termination.
  4. In eukaryotes, the "pre-mRNA" requires modification before it can be used in translation.
    • The 5' end receives a modified nucleotide      , and the 3' end gets a         tail.
    •          are removed from the pre-mRNA and its        are spliced together.
  5. The mRNA exits the nucleus, and translation takes place on            .
    • The genetic information on mRNA is encoded as a sequence of RNA triplets, or         . The     possible codons constitute the genetic code.
    • The           RNA (tRNA)            binds with the mRNA        to add a specific amino acid to the polypeptide chain through          bonds.
    • Translation also has three stages: initiation, elongation, and termination. Summary. Review.
  6.            are changes in the DNA of a cell which may lead to an abnormal          .
    •        mutations are changes in one base pair of a gene.
    • A base-pair               mutation changes one pair of nucleotides.
    • Insertions and deletions of nucleotide pairs may produce             mutations.