1. CHAPTER 16 THE MOLECULE BASIS OF INHERITANCE Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings Section A: DNA as the Genetic Material 1. The search for the genetic material lead to DNA 2. Watson and Crick discovered the double helix by building models to conform to X-ray data

4. 1930’s Hammerling showed that the nucleus was directing cell operations

23. DISULFIDE BRIDGES! So protein did not get passed on to the next generation!

24. Phosphate-Sugar backbone—not found in proteins! So DNA DID get passed on to the next generation!

25. Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings Fig. 16.2b Once more, with feeling!

36. Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings Fig. 16.5

40. CHAPTER 16 THE MOLECULE BASIS OF INHERITANCE Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings Section B: DNA Replication and Repair 1. During DNA replication, base pairing enables existing DNA strands to serve as templates for new complimentary strands 2. A large team of enzymes and other proteins carries out DNA replication 3. Enzymes proofread DNA during its replication and repair damage to existing DNA 4. The ends of DNA molecules are replicated by a special mechanism

53. Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings Fig. 16.14

55. Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings Fig. 16.15

59. Know these enzymes and their function in the replication of DNA

65. The leading strand forms continuously as the bubble enlarges. Once RNA primase has acted, DNA polymerase “chases the fork” in the 5’  3’ direction.

66. Meanwhile, on the other side of the bubble for each original strand, MANY RNA primases and DNA polymerases are needed to “chase the fork”. This is the discontinuous synthesis that makes us refer to it as the lagging strand. OKASAKI fragments are formed—we need another enzyme to “tie” them together.

67. If ALL of the enzymes continue to perform, ELONGATION occurs Those RNA primers must go! Those OKAZAKI fragments must be “tied” together!

68. The primers are removed and replaced with DNA nucleotides by DNA polymerase

69. DNA Polymerase fills in the gaps

74. DNA REPLICATION ANIMATION

75. Extracting DNA in the Laboratory