BIO Chapter 16

  1. Watson and Crick
    figured out the structure of DNA
  2. Chargaff's Rule
    • In any species is an = number of A and T bases and an = number of C and G bases
    • Chargaff's rule expands on complementary base pairing
  3. Purines pair with pyridimines
    • Purine + purine: too wide
    • Pyridimine + pyridimine: too narrow
    • Purine + pyridimine: width consistent with x-ray data
  4. Complimentary base pairing
    Watson-Crick's base pairing model explains Chargaff's rule
  5. Daughter strands
    • 1/2 parent, 1/2 new
    • 2 new daughter strands are built based on the base-pairing rule
  6. DNA replication
    starts replicating at many different spots for efficiency
  7. Helicases
    • enzymes that untwist the double helix at the replication forks
    • "Helicase unzips the suitcase!"- Jenna
  8. Single-strand binding protein
    binds to and stabilizes single-stranded DNA until it can be used as a template
  9. Topoisomerase
    • corrects "overwinding" ahead of replication forks by breaking, swiveling, and rejoining DNA strands
    • stabilizes double helix part
  10. RNA primer
    • starts the replication process
    • brought in by primase
  11. DNA polymerase
    • catalyzes elongation of new DNA at a replication fork
    • attaches free nucleotides to the strand
  12. Antiparallel elongation
    • DNA polymerases add nucleotides only to the free 3' end of a growing strand (<-- replication is only allowed to proceed in one direction)
    • 5' and 3' strands end on different things (5' ends on phosphate, and 3' ends on hydroxide) and they run anti-parallel to each other
  13. Okazaki fragments
    • joined together by DNA ligase
    • series of segments that synthesizes the lagging strand
  14. Mismatch repair
    repairs enzymes; corrects errors in base pairing
  15. Nucleotide excision repair
    nuclease cuts out and replaces damaged stretches of DNA
  16. Telomeres
    nucleotide sequences that postpone the erosion of genes near the ends of DNA molecules
Card Set
BIO Chapter 16
Chapter 16: Molecular basis of inheritance