1. Chapter 27 Prokaryotes Bacteria on the point of a pin

2. Extreme Thermophiles

3. The Three Domains of Life

4. Streptococcus strepto=chain coccus=spherical

5. Bacilli=rod-shaped

6. Spirilla=helical includes spirochetes

7. Largest known prokaryote

8. Another large prokaryote paramecium Prokaryotes vary in size from 0.2µ--750µ

9. Evolution of Prokaryotic Metabolism 1.The Origin of Glycolysis– First prokaryotes 3.5 billion years ago, probably anaerobic chemoheterotrophs. They absorbed organic compounds and used glycolysis (fermentation) to produce ATP in an atmosphere without oxygen 2. The Origin of Electron Transport Chains and Chemiosmosis– The first proton pumps were probably for pH regulation. Later some bacteria used the oxidation of organic compounds to pump H + ’s to save ATP and developed the first Electron Transport Chains. Some got so good at transporting H + ’s that they could actually develop a gradient and use the influx to drive the production of ATP.

10. 3. The Origin of Photosynthesis– The first light absorbing pigments probably provided protection by absorbing UV light. Bacteriorhodopsin in extreme halophiles uses light energy to pump H + ’s out of the cell and produce a gradient which is then used to produce ATP (Photosystem I). Photoheterotrophs 4. Cyanobacteria, Photoautotrophs, Splitting H 2 O and Producing O 2 – Photosystem II evolved in cyanobacteria and they split water and released free oxygen. The oxygen was toxic to many organisms which became extinct. (First Great Extinction) 5. Origin of Cellular Respiration– Some prokaryotes modified their photosynthetic ETC’s to reduce the level of toxic O 2. The purple non-sulfur bacteria still use their ETC’s for both photosynthesis and respiration. Eventually some bacteria used O 2 to pull electrons through proton pumps and aerobic respiration began. aerobic chemoheterotrophs

11. Cell Walls All the proteobacteria and the eubacteria have peptidoglycan cell walls. Archaebacteria have a different type of cell wall. Cell walls protect bacteria from cytolysis in hypotonic solutions but can not protect them from plasmolysis in hypertonic solutions. Mycoplasmas without cell walls are susceptible to both. Penicillin denatures (noncompetitive inhibitor) the enzyme that bacteria use to form their cell walls and leaves them susceptible to cytolysis.

13. Gram-positive diplococcus

14. Gram-positive staphlococcus and Gram-negative diplobacillus

15. Bacillus with Pilli-used for conjugation, attachment to surfaces and snorkels for getting oxygen

16. Bacterial flagella rotate rather than bend

17. Bacteria with flagella

21. Infolding of the plasma membrane give these bacteria respiratory membranes and thylakoid-like membranes

22. Bacteria growing on agar in a petri dish

23. Mold cultures

24. An anthrax endospore

25. Endospores

28. ARCHAEA BACTERIA

29. Extreme halophiles in seawater evaporation ponds that are up to 20% salt; colors are from bacteriorhodopsin a photosynthetic pigment very similar to the pigment in our retinas

30. Hot springs with extreme thermophiles

31. Hydrogen Sulfide Metabolizing Chemoautotrophic Archaea found in sulfur springs

32. Eubacteria

33. The Proteobacteria are a major group (phylum) of bacteria. They include a wide variety of pathogens, such as Escherichia, Salmonella(rod-shaped Gram-negative enterobacteria that causes typhoid fever and the foodborne illness salmonellosis, Vibrio(motile gram negative curved- rod shaped bacterium with a polar flagellum that causes cholera in humans.), Helicobacter(stomach ulcers), and many other notable genera.[1] Others are free-living, and include many of the bacteria responsible for nitrogen fixation. The group is defined primarily in terms of ribosomal RNA (rRNA) sequences, and is named for the Greek god Proteus (also the name of a bacterial genus within the Proteobacteria), who could change his shape, because of the great diversity of forms found in this group.phylum bacteriapathogens EscherichiaSalmonellaGram-negative enterobacteriatyphoid feverfoodborne illnesssalmonellosisVibriogram negativebacteriumflagellum cholerahumansHelicobacter[1]nitrogen fixationribosomal RNA Proteusbacterial genus

34. All Proteobacteria are Gram-negative, with an outer membrane mainly composed of lipopolysaccharides. Many move about using flagella, but some are non-motile or rely on bacterial gliding. The last include the myxobacteria, a unique group of bacteria that can aggregate to form multicellular fruiting bodies. There is also a wide variety in the types of metabolism. Most members are facultatively or obligately anaerobic and heterotrophic, but there are numerous exceptions. A variety of genera, which are not closely related to each other, convert energy from light through photosynthesis. These are called purple bacteria, referring to their mostly reddish pigmentation.Gram-negativeouter membranelipopolysaccharidesflagellabacterial glidingmyxobacteriametabolismanaerobicheterotrophicphotosynthesispurple bacteria

35. Alpha Proteobacteria Rocky Mountain Spotted Fever Ti plasmid Symbiosis with Legumes

36. Alpha Proteobacteria

37. Fruiting bodies of myxobacteriamyxobacteria

38. Helicobacter pylori causes stomach ulcers

39. The Rickettsia are Gram-negative, obligate intracellular bacteria that infect mammals and arthropods. R. prowazekii is the agent of epidemic typhus. During World War I, approximately 3 million deaths resulted from infection by this bacterium. In World War II, the numbers were similar. This agent is carried by the human louse; therefore, disease is a consequence of overcrowding and poor hygiene. Rocky Mountain spotted fever and Q fever remain relatively common.

40. Rhizobium

41. Streptomycetes-soil bacteria that produces an antibiotic

42. Sulfur bacteria that split H 2 S in photosynthesis

43. Cyanobacteria with heterocysts-specialized cells with the enzymes for nitrogen fixation

44. Another Cyanobacteria

47. Cyanobacteria

48. Algae Blooms

49. Bull's-eye rash of a person with Lyme disease Spirochete that causes Lyme disease

50. Bull's-eye rash of a person with Lyme disease

51. Deer tick that carries the spirochetes that cause Lyme disease

52. Spirochete that causes Syphilis

53. Spirochete

54. Mycoplasms that cause Chlamydiae No cell wall and smallest of eubacteria

55. Mycoplasmas-covering a human fibroblast cell

56. Chlamydias living inside an animal cell

57. Mycoplasms that cause Chlamydiae

58. Mutualism of a bioluminescent bacteria in a “headlight fish”

59. The yellow bacillus is a pathogenic bacteria that causes respiratory infections on the membranes inside the nose.

60. The blue bacteria on this slide are commensal living on the membranes inside the nose but causing no harm.

61. Opportunistic infection Koch’s postulates Gram-positive actinomycetes causes tuberculosis destroys tissues Clostridium botulinum releases exotoxins in food it is an obligate anaerobe Vibrio cholerae releases an exotoxin that causes severe diarrhea Salmonella typhi endotoxins that cause typhoid fever, another species of Salmonella causes common food poisoning due to endotoxins explains why it takes 12 -48 hours for symptoms to show up

62. Bioremediation bacteria breakdown sewage

64. Spraying fertilizer on oil spills for Bioremediation

67. Smaller bacteria attacking a larger one

68. Cyanobacteria

69. Conjugation “caught in the act”