1. Cell & Molecular
Biology

4. DNA Replication,
Repair and
Recombination

5. Chapter 6

8. DNA Replication

9. Three models of
DNA replication

10. Figure 6-6 Essential Cell Biology (© Garland Science 2010)

11. Each strand of DNA
in a double helix
serves as a template

12. Base Pairing
is at the heart
of DNA replication

14. Figure 6-4 Essential Cell Biology (© Garland Science 2010)

15. Replication Origins

16. “...positions at which the DNA
is first opened up... usually marked
by a particular sequence of
nucleotides.”

17. Figure 6-5 Essential Cell Biology (© Garland Science 2010)

18. Replication Forks

19. Figure 6-9 Essential Cell Biology (© Garland Science 2010)

20. DNA replication
is bidirectional

21. DNA is
synthesized
5’ to 3’

22. Figure 6-10 Essential Cell Biology (© Garland Science 2010)

23. Figure 6-11 Essential Cell Biology (© Garland Science 2010)

24. Leading and
lagging strands

25. Figure 6-12 Essential Cell Biology (© Garland Science 2010)

26. DNA Polymerase

27. Accuracy

29. Nucleotide addition is catalyzed
only when base-pairing is correct.

30. Figure 6-13 Essential Cell Biology (© Garland Science 2010)

31. Proofreading clips out
added nucleotides that
do not correctly base-pair.

32. Figure 6-14 Essential Cell Biology (© Garland Science 2010)

33. For proofreading to work,
DNA must be synthesized
from 5’ to 3’.

34. Figure 6-15 Essential Cell Biology (© Garland Science 2010)

35. DNA polymerase can
only add nucleotides to
a base-paired nucleotide
in a DNA double helix.

36. So the synthesis of DNA
begins with RNA primers.

37. Figure 6-17a Essential Cell Biology (© Garland Science 2010)

38. Figure 6-16 Essential Cell Biology (© Garland Science 2010)

39. Figure 6-17a Essential Cell Biology (© Garland Science 2010)

40. Figure 6-17b Essential Cell Biology (© Garland Science 2010)

41. The Replication Machine

42. Helicase

43. Single-Strand Binding Protein

44. Sliding Clamp

46. Clamp Loader

47. DNA Primase

48. Telomerase

49. Figure 6-17b Essential Cell Biology (© Garland Science 2010)

50. Figure 6-18 Essential Cell Biology (© Garland Science 2010)

51. DNA Repair

52. Replication Errors

53. Figure 6-21a Essential Cell Biology (© Garland Science 2010)

54. Figure 6-21b Essential Cell Biology (© Garland Science 2010)

55. Figure 6-21c Essential Cell Biology (© Garland Science 2010)

56. Mismatch Repair

57. Figure 6-22 Essential Cell Biology (© Garland Science 2010)

58. DNA Damage

59. Depurination
Deamination

60. Figure 6-23 Essential Cell Biology (© Garland Science 2010)

61. Figure 6-25a Essential Cell Biology (© Garland Science 2010)

62. Figure 6-25b Essential Cell Biology (© Garland Science 2010)

63. Thymine
Dimerization

64. Figure 6-24 Essential Cell Biology (© Garland Science 2010)

65. Repair:
1. excision
2. resynthesis
3. ligation

66. Figure 6-26 Essential Cell Biology (© Garland Science 2010)

67. Double-Stranded Breaks

68. Nonhomologous
End-Joining

69. Figure 6-27 Essential Cell Biology (© Garland Science 2010)

71. Homologous
Recombination

72. “...the exchange of
genetic information
between a pair of
homologous DNA molecules...”

73. Double-stranded
break repair

74. Figure 6-31 (part 1 of 2) Essential Cell Biology (© Garland Science 2010)

75. Figure 6-31 (part 2 of 2) Essential Cell Biology (© Garland Science 2010)

76. Meiosis

77. Page 183

79. Figure 6-30 Essential Cell Biology (© Garland Science 2010)

80. Figure 6-31 (part 1 of 2) Essential Cell Biology (© Garland Science 2010)

81. Figure 6-31 (part 2 of 2) Essential Cell Biology (© Garland Science 2010)

82. Mobile
Genetic
Elements

83. or,
Transposons

84. DNA-Only Transposons

85. 3 Bacterial Transposons
Figure 6-32 Essential Cell Biology (© Garland Science 2010)

86. Transposase

87. Figure 6-33 Essential Cell Biology (© Garland Science 2010)

88. Retrotransposons

89. Figure 6-34 Essential Cell Biology (© Garland Science 2010)

90. Reverse Transcriptase