The document summarizes DNA replication, repair, and recombination. It discusses the key components and processes involved in DNA replication, including replication origins, forks, primers, and polymerases. It also examines DNA repair mechanisms for errors, damage like depurination, and double-stranded breaks. Finally, it briefly touches on mobile genetic elements and retrotransposons that can move locations in the genome.

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