1. DNA History, Structure, and Replication (4.1) Part 1
Pre-AP Biology
DNA History, Structure, and Replication (4.1)
Part 1

2. Alfred Hershey & Martha Chase

3. Bacteriophage injecting its DNA into the host cell.

4. Electron Microscope View of Bacteriophages on the host cell.

5. Hershey-Chase experiment

6. Erwin Chargaff

7. Adenine = Thymine (DNA) or Uracil (RNA)
Chargaff’s Rule
Adenine = Thymine (DNA) or Uracil (RNA)
&
Guanine = Cytosine
If you know the % composition of 1, you can find the % composition of the other 3.

8. Rosalind Franklin

9. Franklin’s X-ray crystallography of DNA molecule.

10. DNA from a side view

11. James Watson & Francis Crick with their DNA model

12. Base Pairing & Hydrogen bonding

13. DNA History, Structure, and Replication (4.1) Part 2
Pre-AP Biology
DNA History, Structure, and Replication (4.1)
Part 2

14. S Phase of Cell Cycle

15. Complimentary base pairing See how the dark blue strand is half (“semi”) of the new strand?

16. Origins of Replication & Replication Bubbles

17. Elongation using DNA Polymerase III

18. DNA Replication by adding Nucleosides on the 3’ end
New strand
Template strand
5¢ end
3¢ end
5¢ end
3¢ end
Sugar
Base
Phosphate
DNA polymerase
3¢ end
3¢ end
Pyrophosphate
Nucleoside
triphosphate
5¢ end
5¢ end

19. 5 Carbon Sugar Important Parts (It could be DNA or RNA)

20. Lead strand(top) versus Lagging strand (bottom) Helicase is the GREEN “blob”

21. RNA Primer (“starting point”)

22. Nucleotide Excision Repair