1. Viruses & Bacteria Chapter 21

2. Viral Structure All viruses have 2 main parts: Capsid– protein encasement DNA or RNA – genetic information.

3. Lytic Cycle: Virus attaches and inserts DNA / RNA Viral genome is replicated. Host cell makes new viral parts. New viruses are assembled. Host cell is lysed, Viruses are released. Lets, watch it!

4. Lysogenic Cycle: HOST NOT KILLED AT START! PROVIRUS forms stores viral DNA At some point enters Lytic! Lets, watch it!

5. Vaccines: Contain parts of “microbe” (bacteria / virus), heat killed microbe, weakened microbe. Immune system responds to the microbe. When you are infected by the actual microbe your immune system fights it fast and furious…before you can actually get sick.

6. Antivirals: Stop it from binding to the cell. Stop it from copying its DNA / RNA. Stop it from being able to make protein coat from DNA / RNA. Think about viral life cycle. Where could we stop it? No attachment! No new virus parts! NO NEW VIRUS!

7. Papilloma virus

8. Herpes Virus

9. Pox Virus

10. Picornaviruses Polio

11. Myxoviruses: common cold

12. Rhabdoviruses

13. Retroviruses: HIV Use Reverse Transcription once inside the cell to make DNA.

14. BacteriaBacteriaBacteriaBacteria

15. Bacteria are very small…

16. This is a pore in human skin, the yellow dots are bacteria:

17. Bacterium This bacterium is much smaller than the white blood cell that is about to “eat” it:

18. Clean skin has about 20 million bacteria per square inch:

19. Evolution / Classification: Most ancient organisms Most numerous on Earth Microscopic, unicellular Prokaryotes Autotrophic & Heterotrophic Two Domains: –Archaebacteria & Eubacteria

20. Archaebacteria – 3 Types: Methanogens: live in Anaerobic environments– no O 2 Halophiles: live in high salt concentrations– Great Salt Lake, Dead Sea Thermophiles: live in acidic, hot waters – Hot springs, volcanic vents

21. Eubacteria – 3 Types Heterotrophs – obtain nutrients from others – may be parasites or saprophytes (decomposer). Photosynthetic autotroph – e.g. Cyanobacteria – contain chlorophyll and undergo photosynthesis. Chemosynthetic autotroph – chemosynthesis. They use inorganic compounds, such as nitrogen & sulfur to make food. e.g. Nitrogen fixation

23. Structure of Bacteria – Be able to label.

24. Antibiotics: 1928 – Sir Alexander Fleming Discovered Penicillin from mold that contaminated his petri dish. Penicillin was the first antibiotic! Zone of Inhibition

25. Common Antibiotics AntibioticMechanismTarget bacteria PenicillinInhibits cell wall synthesisGram Positive AmpicillinInhibits cell wall synthesisBroad spectrum BacitracinInhibits cell wall synthesisGram Positive – Skin Ointment CephalosporinInhibits cell wall synthesisGram Positive TetracyclineInhibits Protein SynthesisBroad spectrum StreptomycinInhibits Protein SynthesisGram Neg. tuberculosis Sulfa drugInhibits cell metabolismBacterial meningitis, UTI RifampinInhibits RNA synthesisGram Pos., some Neg. QuinolinesInhibits DNA SynthesisUTI

26. Identifying Bacteria: 3 Basic Shapes Coccus (Cocci) - sphere Bacillus (Bacilli) – rod Spiral Prefixes: –Diplo – growing in pairs –Staphylo – growing in groups resembling grapes –Strepto – growing in chains

27. Cocci are sphere shaped:

28. Bacilli are rod shaped:

29. Spirillium bacteria are corkscrew shaped:

30. Diplo appear in pairs, such as diplococcus bacteria that cause gonorrhea:

31. Staphylo bacteria occur in clumps, such as Staph. Infections.

32. Strepto bacteria occur in chains, such as Strep. Throat:

33. Spirillium: Lyme Disease

34. Use the terms in combinations to describe bacteria: StreptococcalStaphylococcal

35. Can you name these bacteria? StreptobacilliDiplococci Spirilli StreptococciStaphylococci

36. Bacterial Reproduction: Fission

37. Bacterial Reproduction: Conjugation

38. Transduction – 1. Virus infects bacterium. 2. Bacterial cell produces new virus parts. 3. A virus accidentally picks up a section of the bacterial chromosome…instead of viral. 4. That virus can still infect another bacterial cell. 5. Potential new gene incorporates into new bacterial genome. Could be antibiotic resistance!

39. Bacteria & Disease DiseasePathogenAreas affected Mode of transmission BotulismClostridium botulinumNervesImproperly preserved food CholeraVibrio choleraeIntestineContaminated water Dental CariesStreptococcus mutans, sanguis, salivarius TeethEnvironment to mouth GonorrheaNeisseria gonorrhoeaeUrethra, fallopian Sexual contact Lyme diseaseBerrelia burgdorferiSkin, jointsTick bite Rocky Mountain SF Rickettsia recketsiiBlood, skinTick bite Salmonella IntestineContaminated food, water Strep throatStreptococcus pyogenesURT, blood, skin Sneezes, coughs, etc. TetanusCostridium tetaniNervesContaminated wounds TuberculosisMycobacterium tuberculosisLung, bones coughs

40. Helicobacter pylori can cause ulcers:

41. Leprosy is a bacterial infection that decreases blood flow to the extremities resulting in the deterioration of toes, ears, the nose and the fingers. Mycobacterium leprae

42. Botulism – Botox

43. Cholera: Vibrio cholerae – produces enterotoxin (toxin released in the intesting) The enterotoxin changes sodium movement in intestines and the person could lose up to 6 liters of water per day. Dehydration – leading to low blood pressure causes death

44. Salmonella

45. Strep Throat

46. Tuberculosis Evolutionary Arms Race Episode 1Episode 2

47. Tetanus

48. Endospore:

49. Useful Bacteria: N 2 Fixation Nitrogen fixing bacteria in soybean roots. Usually found on roots of legumes. We depend on these bacteria for nitrogen! We get our nitrogen (DNA/RNA) from eating plants.

50. Useful Bacteria: Food Bifidobacteria are beneficial to the gastro-intestinal tract. They are also called probiotic bacteria. Streptococcus lactis and other lactic acid bacteria are used to make cheese. They ripen the cheese and provide characteristic flavour. Streptococcus thermophilus is one of the major yogurt- forming bacteria. The other is Lactobacillus bulgaricus

51. Useful Bacteria: Environmental Clean-Up Pseudomonas putida