Bacteria & Archaea: Themes of Diversity

1. Bacteria & Archaea: Themes of Diversity Chapter 28 Dr Karen 9/26

2. Announcements • Dave Temmermand (one of my former students) will be speaking at the pre-SOMA meeting • HJPatterson 1104 • This Wednesday 5:30 pm • Dave is currently an osteopathic medical student at UMDNJ

4. Quiz #3 • Technical difficulties – not able to load quiz • It opened up last night • It will remain open till 11 am on Wednesday (day of exam 1)

5. Exam on Wednesday • #2 pencils and erasers - scantron • Pen for short answer • UID # • Last names Armory room 0110 A to C Physics D to Z Exam will cover part way through today – clearly marked!!

6. Where is the armory?? M

7. Table 28.1

8. Fig 7.3

9. Cell wall vs plasma membrane • No cell wall in animals and protozoa • Cell wall found in • Plants • Bacteria • Fungi • Algae • Archaea • Cell wall composed of polysaccharides

10. Fig 5.3: Review of Sugar StructureMonomers can form polysaccharides

11. Fig 5.4a: α linkage

12. Table 5.1a: Starch and glycogen (energy storage)

13. Figure 5-5b-Table 5-1 Table 5.1c: Cellulose

14. Figure 5-5b-Table 5-1 Table 5.1c: Cellulose

15. Table 5.1e: Peptidoglycan

16. Function of cell wall: rigidity H2O High [solute] Bacterial cell Result = hydrostatic pressure for structure

17. Table 5.1e: Peptidoglycan:Bacterial Cell Walls

18. Table 5.1c: Cellulose:Cell walls of Eukarya & some Archaea

19. Lipid micelles Lipid bilayers Fig 6.5: Membrane Phospholipids No water Hydrophilic heads interact with water Hydrophobic tails interact with each other Hydrophilic heads interact with water

20. Fig 6.4: Membrane Phospholipids Phospholipid Polar head (hydrophilic) Nonpolar tail (hydrophobic)

21. Membrane lipid side chains

22. Archaea plasma membranes

23. Phospholipids Archaea Bacteria / Eukarya

24. Membrane Phospholipids

25. Fig 6.9

26. Fig 6.11 Hydrocarbon chain affects fluidity : Liquid vs solidSaturation & chain length

27. Fig 6.10:Unsaturation:More Fluid& Morepermeable

28. To make a membrane more fluid: • Decrease length of phospholipid fatty acid or isoprene side chains • Increase degree of unsaturation (increase # of double bonds) in fatty acid side chains • NOTE: reverse is true to decrease fluidity

29. Table 28.1

30. Evolutionary Themes & Diversification of Bacteria and Archaea Remember why the rate of evolution and the generation of diversity is high!

31. Answer: • Large number of organisms involved • Short generation time • i.e., many DNA replications/time • Genetic redundancy • Rapidly changing environment in many cases (selective pressures) • Plasmids = lateral gene transfer

32. Evolutionary Themes & Diversification of Bacteria and Archaea • Morphological Diversity • Metabolic Diversity

33. Fig 27.11: Morphological Diversity Mycoplasma Bacillus anthracis T. namibiensis Rhodo-spirllum

34. Characterize membrane by Gram staining Gram-positive cells retain Gram stain more than Gram-negative cells do. Gram-positive cells Gram-negative cells Figure 28-14a

35. Fig 28.14

36. Fig 28.14 Cell walls in Gram-negative bacteria have some peptidoglycan and an outer membrane. Gram-negative cell wall Polysaccharides Cell wall Outer membrane Peptidoglycan Plasma membrane Protein

37. Metabolic diversity Autotrophs Heterotrophs

38. Metabolic diversity Autotrophs Heterotrophs

39. Things to know to this point… • Table - differences among 3 major groups of organisms • Mechanisms for generating genetic diversity in Archaea and Prokaryotes • Types and structures of carbohydrates and lipids in extracellular cell walls • rRNA & FtsZ (I am pulling this stuff right out of your textbook!)

40. EXAM TO HERE • This is as far as the exam will cover

41. Chapter 28: Things to Examine • Diseases • Bioremediation • Extremophiles • Global Change (revisited later today and in the semester) • Nitrogen Cycle and “Dead Zones”

42. Diseases: The Plague • Yersinia pestis • Rod shaped • Facultative anaerobe

43. Diseases: The Plague • Killed over 100 million people • China lost 1/2 of its population • Europe lost 1/3

44. http://en.wikipedia.org/wiki/File:Bubonic_plague_map.PNG

45. Y. pestis • Life cycle utilizes a mammalian host and a flea host • Lives embedded in a biofilm in gut of flea • Flea tries to eat but regurgitates blood into host

46. Y. pestis : evolution at its most dangerous • Produces a number of specific proteins that insure growth in host • Prevents blood clots in host • Prevents detection by host immune system • Induces apoptosis (death) by host macrophages (phagocytic cells of host immune system) • Kills host lymphocytes

47. BioremediationPossible because of prokaryotic diversity • Inventor: George M. Robinson • 1960’s in Santa Marie CA • Petroleum engineer • Invented “Bug-Brews”

48. Robinson’s Strategy: selection O I L Collection or soup of microbes Surviving bacteria metabolize or detoxify components of oil

49. Example of this strategy:

50. Other attempts: Exxon Valdezoil spill (11 million gallons of crude oil); March 1989