1. Exam #1 is T 9/23 in class
(bring cheat sheet)
Available M 9/22: 10am-noon, 1:30-2:30pm, and after 3:30pm.
T 9/23 after 10am

2. How do cells express genes?

3. Tbl 12.3

4. A processed mRNA ready for translation
5’ untranslated region
3’ untranslated region

5. Sometimes RNA is the final product.

6. The ATM repair pathway inhibits RNA polymerase I transcription in response to chromosome breaks
Michael Kruhlak, Elizabeth E. Crouch, Marika Orlov, Carolina Montano, Stanislaw A. Gorski, Andre Nussenzweig, Tom Misteli, Robert D. Phair & Rafael Casellas
Nature Vol 447 pg June 2007

7. How does DNA damage affect transcription?
The ATM repair pathway inhibits RNA polymerase I transcription in response to chromosome breaks
Michael Kruhlak, Elizabeth E. Crouch, Marika Orlov, Carolina Montano, Stanislaw A. Gorski, Andre Nussenzweig, Tom Misteli, Robert D. Phair & Rafael Casellas
Nature Vol 447 pg June 2007

8. rRNA is transcribed by RNA polymerase I

9. comprised of rRNA

10. rDNA and transcription of rRNA

11. rDNA is arranged in repeated transcription units
Fig 12.16

12. Fig 12.16
One transcript is then processed into the three major components of ribosomes

13. How can you measure transcription?
Fig 1a

14. DNA damage inhibits rRNA transciption
0 Gy
10 Gy
Fig 1a

15. More irradiation leads to less transcription
Fig 1a

16. Transcription arrest is transitory
Fig 1b

17. DNA damage by laser. Only damaged nucleoli show decreased transcription.
Fig 1c

18. What cellular components are involved?
Ku has been shown in vitro to inhibit RNA pol I after DNA damage.
Atm kinase is part of signal transduction following DNA breaks.
Fig 2a

19. Atm must be phosphorylated to mediate the decrease in transcription
Fig 2b

20. Brca1, H2ax, Ku80, and 53bp1 are involved in DNA repair
Brca1, H2ax, Ku80, and 53bp1 are involved in DNA repair. Transcription arrest occurs, but resumption is delayed.
Fig 2c

21. DNA damage arrests rRNA transcription via ATM

23. Combinations of 3 nucleotides code for each 1 amino acid in a protein.
Fig 13.2
Combinations of 3 nucleotides code for each 1 amino acid in a protein.

24. The Genetic Code: 64 codons 20 amino acids 1 start codon 3 stop codons
Tbl 13.2
The Genetic Code:
64 codons
20 amino acids
1 start codon
3 stop codons

25. Translation involves different RNA’s
Fig 12.1
Translation involves different RNA’s
Protein

26. rRNA folds up by intramolecular base pairing
Fig 13.16

27. Ribosomes are made of both RNA and protein
Fig 13.15

28. On the ribosome, the mRNA, tRNA’s, and growing polypeptide come together
Fig 13.16

29. The structure of transfer RNA
Fig 13.12
The structure of transfer RNA

30. Fig 13.19
Translation initiation sequences along with the start codon signals the start of translation

31. Translation initiation in eukaryotes
Fig 13.18

32. The poly-A tail and 5’ cap are involved in translation initiation

33. The Genetic Code: 64 codons 20 amino acids 1 start codon 3 stop codons
Tbl 13.2
The Genetic Code:
64 codons
20 amino acids
1 start codon
3 stop codons

34. Fig 13.14
Redundancy in codons means that some tRNAs bind to the codon via wobble

35. mRNAs are usually translated by multiple ribosomes simultaneously

36. In bacteria, transcription and translation occur simultaneously
Fig 13.22

37. Termination of translation by binding of release factor (a protein) to the stop codon
Fig 13.21

38. All protein interactions in an organism (C
All protein interactions in an organism (C. elegans) compose the interactome

39. post-translational modifications: activation, inactivation, destruction, and translocation
RNA synthesis
Protein

40. How do cells express genes?

41. Exam #1 is T 9/23 in class
(bring cheat sheet)
Available M 9/22: 10am-noon, 1:30-2:30pm, and after 3:30pm.
T 9/23 after 10am