3. Structures of the Purine and Pyrimidine Bases

4. Example of the Structure of a Nucleotide Base Nucleoside Nucleotide

5. Chemical Structure of a Nucleic Acid Voet Fig. 3-6

6. Note that the strands run antiparallel Note that the helix is 20 Å wide. There are about 10 base pairs per turn of the helix. One turn of the helix is 34 Å The base pairs are 3.4 Å apart Double Helical Structure of DNA Voet Fig. 3-9 Major groove

8. Base Pairing Voet Fig. 23-1

9. Many proteins associate With DNA through the Major and Minor grooves Major Groove http://www.clunet.edu/BioDev/omm/gallery.htm

10. Space-filling Model of B-DNA Backbones of the strands are bright green and bright red The bases on the corresponding backbones are lighter green and pink

11. Helical Structures A-DNAB-DNAZ-DNA Voet Fig. 23-2

12. Supercoiling of DNA Supercoiled DNARelaxed DNA

13. Denaturation of DNA Voet Fig. 23-15

14. Restriction Endonucleases Voet Fig. 3-18

15. Cutting DNA with Restriction Endonucleases followed by Analysis by Gel Electrophoresis Restriction Digest A B C A C B

16. Visualizing DNA Fragments in Gels Voet Fig. 3-20

17. Southern Analysis Voet Fig. 23-28

18. Chain Termination Method of DNA Sequencing Voet Fig. 3-23

19. Fluorescent dye-conjugated derivatives of the Dideoxynucleotides can be used in DNA Sequencing Instruments DNA Sequencing Instruments

20. Example of data obtained from a DNA sequencing reaction using fluorescent (dye-conjugated) derivatives of dideoxynucleotides Automated Sequencing Voet Fig. 3-25

21. Polymerase Chain Reaction Amplification of DNA Garrett and Grisham Fig. 13-21 See Voet Fig. 3-32

22. Plasmids can Serve as Cloning Vehicles (Vectors) Voet Fig. 3-27

23. Construction of a Recombinant DNA Voet Fig. 3-29

24. Vector DNAs must be capable of replicating in the host cells and must carry a selectable marker Selection of Transformants

25. Selection of Transformants of Interest Voet Fig. 3-31