1. TRANSCRIPTION : Prokaryote Eukaryote DNA : Template strand Coding strand

2. Promoter / Terminator Upstream / Downstrean Startpoint

5. Phosphodiester bond formation 3’-OH group of the last nt. 5’ triphosphate of incoming nt. RNA chain Pyrophosphate - Reaction rate in bacteria 40 nts. / sec. At 37 ๐ C - Translation rate 15 amino a / sec (the same) - DNA replication rate 800 bp. / sec (faster)

6. Four stages of Transcripti on Template recognition Initiati on Elong ation Termi nation

7. Holoenzyme = initiate transcription Core enzyme = synthesize RNA Sigma factor = recognize specific binding sites

10. TERMINA TION - Intrinsic Terminator - form hairpin in a secondary structure of RNA. - G.C rich region - 7-9 bases of U-run Rho-dependent terminator: 50-90 bases rich C and poor G protein size ~ 46 KD

11. Rho factor pursues RNA poly. along the RNA and can cause termination

12. ANTITERMINATION Mechanism in bacterial phages

13. Sigma factor

14. Jacob & Monod (1961): The model for control of gene expression in bacteria Two types of seq. in DNA: seq. that code for trans-acting product (usually proteins) cis-acting sequences (usually sites in DNA). A structural gene: any gene that codes for protein (or RNA) products A recgulator gene: structural gene that codes for a protein involved in regulating the expression of other genes The lac structural genes in bacteria, lac ZYA

15. Negative control ; a trans- acting repressor bine to cis-acting operator to turn off transcription.

16. Positive control; trans- acting factors bind to cis-acting sites in order for RNA polymerase to initiate transcription at the promoter

17. opera tor