Microbial Genetics

1. Microbial Genetics • I. Structure and function of DNA and genes • II. Gene expression in bacteria • III. Mutation and variation • IV. Horizontal gene transfer in bacteria

2. Nucleotides of __________________ ___________ (RNA)

3. Nucleotides of ____________________ Acid (DNA) Note the numbering of the carbon atoms

4. “Growth” (__________________________) of a single DNA strand 5’ 3’ 5’ 5’ 3’ 3’ But RNA also polymerizes like this Note: this is __________

5. “_____________” arrangement of the two strands of a DNA molecule 5’ end 3’ end 5’ end 3’ end

6. The ‘base’ component of a nucleotide -- ________________ Guanine G Adenine A

7. The ‘base’ component of a nucleotide -- _________________ Thymine T Uracil U Cytosine C

8. or _______ Note that this is ribose. What would deoxyadenosine triphosphate (dATP) look like?

9. The amount of adenine = the amount of ___________ and the amount of cytosine = the amount of ____________ in a cell

10. DNA Secondary Structure • See text, Fig. 9.4

11. Overview

12. DNA replication

13. Replication of the bacterial ________________

14. DNA Replication -- First Steps

15. DNA Replication -- First Steps (cont)

17. DNA structure and replication

18. Flow of genetic information in cells

19. Information processing in _____________

20. Information processing in _____________

21. Text, Fig. 9.18

22. Promoter region -- where RNA polymerase binds to initiate _____________________ • One gene ---> one _______________

23. DNA Transcription

24. Transcription Animation • http://www.microbelibrary.org/FactSheet.asp?SubmissionID=378

25. Text, Fig. 9.13

26. Text, Fig. 9.13

27. Text, Table 9.3

28. The Ribosome A ribosome's true colors. (Top) The large subunit of the ribosome seen from the viewpoint of the small subunit, with proteins in purple, 23S rRNA in orange and white, 5S rRNA (at the top) in burgundy and white, and A-site tRNA (green) and P-site tRNA (red) docked according to (5). (Bottom) The peptidyl transfer mechanism catalyzed by RNA

29. Translation: tRNA ________________ RNA (tRNA)

30. Prokaryotic Translation • Animation • http://www.microbelibrary.org/FactSheet.asp?SubmissionID=379

31. Translation: the ribosome

32. Translation: _______________

33. Translation: Elongation (cont.)

34. Translation: Elongation (cont.)

35. Translation

36. Text, Fig. 9.17

37. Replication problem • Give the sequence of the strand replicated from the following strand: • 5’- GTT ATT CCC GTA ATC GGC TAG - 3’ • Answer: • 3’- __________________________________ - 5’ • Which direction relative to the original strand, left or right, would the polymerase move as it makes this strand? • Answer: _____________

38. Transcription Problem • Assume that the strand just produced is the sense strand (the strand encoding the mRNA): • 3’- CAA TAA GGG CAT TAG CCG ATC - 5’ • What would be the sequence of the mRNA transcript of this portion of the gene? Be sure and include 5’-3’ orientation. • Answer: • ____________________________________

39. Translation problem • Translate your transcript using the following codon table

40. 5’- GUU AUU CCC GUA AUC GGC UAG - 3’ • Answer: • ____ ____ ____ ____ ____ ____ ____

41. Problem • Here is a portion of the sense strand of a gene: • 5’ – T A C C G A C C T T T G A G A A C T T G A – 3’ • 1) What would be the sequence of the strand which is replicated from this strand (be sure to note the 5’-3’ orientation of the strand)? • 2) Which direction would the DNA polymerase move as it replicates this (sense) strand: • a. <---------- Left • b. ----------> Right • 3) What would be the sequence of the mRNA transcript of this portion of the gene (include orientation)? • 4) Translate using the codon table.