Ch 13 DNA and its Role in Heredity

  1. tracsforming principle
    can produce a haritable change from a dead cell
  2. purines
    • Adenine (A)
    • Guanine (G)
  3. Pyrimidines
    • Cytosine (C)
    • Thymine (T)
  4. DNA Base Rule
    • A=T
    • C=G
  5. helical
    in the shape of a helix
  6. antiparellel
    to chains of DNA run in opposite directions
  7. Key features of DNA structure
    • double stranded helix
    • right handed twist
    • antiparallel
    • outer edges of N bases are exposed in major and minor grooves
  8. DNA Functions
    • Stores genetic info
    • suseptible to mutation
    • preciselt replicated in cell division
    • genetic material expressed as phenotype
  9. semiconservative
    parent serves as a template and new molecules have one old and one new strand
  10. conservative
    original helix only serves as a template
  11. dispersive
    parent fragments serve as templates assembling old and new parts into a melecule
  12. steps in DNA replication
    • double helix is unwound making 2 template strands
    • new nucleotides are added
  13. replication complex
    a large protein complex that interacts with the template strands
  14. primer
    • starter strand
    • complimentary to DNA template
  15. primase
    enzyme that synthesizes DNA one nucleotide at a time
  16. DNA helicase
    protien that uses energy from ATP hydrosis to unwind DNA
  17. Single-strnad Binding proteins
    protein that keeps strands from getting back together
  18. replication fork
    the site where DNA unwinds to expose bases
  19. leading strand
    • new strand
    • oriented to grow at its 3' end as fork opens
  20. lagging strand
    oriented so that its exposed 3' end gets further from fork
  21. okazaki fragments
    • form in laging strand
    • small discontinuous stretches
  22. DNA Ligase
    • catalyzes the last phosphdiester linkage between fragments
    • closes gaps left in backbone by Okazaki fragments
  23. processive
    catalyze many polymerizations each time they bind to DNA
  24. Sliding DNA clamp
    a protien that stabilizes newly replicated strands
  25. Polymerase chain reaction (PCR)
    makes copies of DNA sequences
Card Set
Ch 13 DNA and its Role in Heredity
Biology Lecture Ch 13,