Chapters 18 & 19

1. Chapters 18 & 19 Bacteria Viruses & Operon Systems

2. Key Topics for Ch. 18 & 19 Chapter 18 TopicPgs. Viruses: DNA, RNA (retroviruses) 334-342 Lytic & Lysogenic Cycle 337-339 Bacteria: Genetic recombination 346-350 Plasmids & Conjugation Transformation (Lab) Transposable elements 351-352 Lac Operon System 353-356 Regulating Gene Expression Chapter 19Pgs. DNA & Chromatin packing into chromosomes 360-361 Oncogenes & Tumor-supressor genes (Cancer) 370-373 Transposons (B. McClintock) w/Indian corn 375

3. DNA & RNA Viruses See Pgs. 340

4. Lytic & Lysogenic Cycles of a Virus(Lysogenic:host is not destroyed)

5. 5 Classes of Viruses-Pg. 340

6. Examples of Common Viruses DNARNA Herpesvirus Ebola Poxvirus Infuenza Papovirus (warts) HIV Measels, Mumps Rabies West Nile

7. HIV Infection (pgs 340-342)

8. HIV infection on a White Blood Cell

9. Invasion of a Virus

11. Relative size Differences between of Viruses, Prokaryotes, and Eukaryotes

12. Bacterial Reproduction of DNA

13. Transduction

14. Conjugation and the transfer of the F Plasmid http://highered.mcgraw-hill.com/sites/0072437316/student_view0/chapter20/animations.html

15. Transformation • Uptake of foreign DNA from the environment • What we did in our lab (pGLO plasmid)

16. Detecting Genetic Recombination in Bacteria (pg. 347)

17. Insertion Sequences & Transposable Elements (pgs. 351-352) • Always a part of of chromosomal or plasmid DNA • Sometimes called “jumping genes”-never detach • Inverted sequences are on each side of an insertion sequences. (See pg. 352) • A single gene for coded for: transposase Specialized plasmids are constructed using these sequences. http://highered.mcgraw-hill.com/sites/0072437316/student_view0/chapter20/animations.html

18. Jacob & Monod • Discovered Lac Operon • Nobel Prize for Discovering Control of Gene Expression

19. Regulation of a Metabolic Pathway

20. Specialized Genes • Operator = "on/off" switch for operon • Regulator = makes repressors to turn off an entire operon • Repressor = Binds to operator, turn off gene expression • Inducer = Joins with an active repressor, activates it • Co-repressor = Joins with inactive repressor, converts it to active

21. OPERON THEORY • Operon = group of structural genes regulated as a unit • Several genes controlled by an operator site

22. Operon Complex • RNA Polymerase must bind to the promoter site and continue past the operator site to transcribe mRNA

23. Repressible Operons (trp operon) • Usually “ON” - to turn OFF: • Co-repressor needs to bind to an inactive repressor and activate it • RNA Polymerase then cannot bind and transcribe mRNA Ex. trp operon is a repressible operon: -trancription is usually on -inhibited only by tryptophan (corepressor)

25. Trp Operon when Tryptophan is Absenthttp://highered.mcgraw-hill.com/sites/0072437316/student_view0/chapter18/animations.html#

26. INDUCIBLE Operons (ex. lac operon) • Usually “OFF” - to turn ON: • INDUCER needs to bind to an active repressor and inactivate it • RNA Polymerase can then bind and transcribe mRNA Ex. Lac operon is an inducible operon

27. Lac Operon • Lactose ONLY used when glucose is not present in large quantities • When glucose is present, cAMP levels are low, cAMP cannot bind to CAP and initiate enzyme production

28. Inactive Repressor-Lactose Presenthttp://highered.mcgraw-hill.com/sites/0072437316/student_view0/chapter18/animations.html

29. Lac Operon • In absence of glucose, cAMP levels are HIGH, binding to CAP can occur • Beta-Galactosidase is made

30. Lac Operon • RNA polymerase only binds efficiently when cAMP-CAP complex is in place • Lac Operon = an INDUCIBLE Operon • Lactose = an INDUCER • Binds to repressor and inactivates it

31. Lac Operon Summary

32. Key Concepts for Chapter 19 • Review of DNA & Genome 359-362 • Oncogenes & Proto-Oncogenes 370-373 • Tumor Supressor Genes • McClintok’s transposons 375-376

33. Chromatin Def: complex of DNA and proteins DNA Packing Histone proteins (+ charged amino acids w/ phosphates of DNA that are - charged) Nucleosome -”beads on a string”; basic unit of DNA packing Heterochromatin -highly condensed interphase DNA (can not be transcribed) Euchromatin -less compacted interphase DNA (can be transcribed)

34. The Biology of Cancer (review) Oncogenes & Tumor Suppressor Genes (RAS gene) (p53 gene)

35. Molecular Biology of Cancerpgs. 370-371 I. Proto-oncogene -----convert into Oncogenes -Controls cell growth (cell cycle & levels of cyclin) -Analogy: gas pedal is stuck in the down position ***Possible Causes: -movement of DNA &/or chromosome fragments -amplification; increases the number of copies of proto-oncogene -point mutation; protein product is altered II. Tumor-suppressor genes -Considered the “Guardian Angel gene” -Example (p53 gene) -Analogy: Break pedal is stuck in the up position

37. Assignt. Packet #3 (Ch. 16-20) • Cover sheet: (Name, Period, Unit #3 Ch. 16-20) • Pre-Lab: Bacteria Transformation (pGlo lab) – pick up • Pre-Lab: Analysis of Lambda DNA w/Gel Electrophoresis • Videos: • True Story of the Elephant Man • DNA Blueprint of Life (3 segments) • Cracking the Code of Life • Using DNA Fingerprinting to solve crimes (2 cases shown) • IQ’s x6 • Cumulative Practice test (40 Quest.) – Printout results ****Be sure to Choose Chapters 16-20

38. Test #3 Breakdown (Ch. 16-20) # Questions • Chapter 16: History/Discovery of DNA replication 15 • Chapter 17: Protein Synthesis (gene expression) 18 • Chapter 20: Recombinant DNA Technology 14 • Chapter 18: Gene regulation & Viruses 8 • Chapter 19: Cancer Review/Transposons 2 • Lab: 6 • Cumulative Quest. (Ch. 1-19): 12 ____________________________________________________ TOTAL Questions: 75 Topics to review: Proteins (struct. & function)-x2, Cell Respiration (glycolysis & Kreb) , Diffusion/osmosis, Membrane fluidity, Genetic cross (Mendelian), Enzyme function, chromosome number after mitosis or meiosis.