1. Gene structure DNA replication

15. Figure 7.4A

16. Figure 7.5 16

17. DNA Structure
The DNA double helix has grooves: a wide major groove and a narrow minor groove.
- These provide DNA-binding proteins access to base sequences.
Figure 7.6 17

18. RNA Structure RNA differs from DNA: - Usually single-stranded
- Contains ribose sugar
- Uracil replaces thymine
Figure 7.4B 18

19. The Bacterial Nucleoid
Bacteria pack their DNA into a series of loops or domains, collectively called the nucleoid.
- Loops are anchored by histone-like proteins
Figure 7.8 19

20. DNA Replication
Replication of cellular DNA in most cases is semiconservative.
- Each daughter cell receives one parental and one newly synthesized strand.
Figure 7.13 20

21. Figure 7.14 21

22. Figure 7.15 22

23. Figure 7.18b
Figure 7.18a 23

24. Click box to launch animation
DNA Replication
Animation: DNA Replication
Click box to launch animation

25. Figure 7.19 25

26. Figure 7.21 26

27. Analysis of DNA
Figure 7.27A
Restriction endonucleases cleave DNA at specific recognition sites, which are usually 4 to 6 bp and palindromes.
- May generate blunt or staggered ends 27

28. Analysis of DNA
Agarose gel electrophoresis can be used to analyze the DNA fragments obtained by treatment with restriction enzymes.
Figure 7.27B 28

29. Analysis of DNA
The polymerase chain reaction (PCR) can produce over a million-fold amplification of target DNA within a few hours.
Figure 7.29 29