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Bacteria & Viruses

Bacteria & Viruses. BACTERIA. Prokaryotic = no nucleus Unicellular = one cell Mostly heterotrophic = cannot make own food. Two Kingdoms of Bacteria:. (Based on differences in structure of DNA, cell wall and cell membrane). Eubacteria and Archaebacteria.

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Bacteria & Viruses

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  1. Bacteria & Viruses

  2. BACTERIA • Prokaryotic = no nucleus • Unicellular = one cell • Mostly heterotrophic = cannot make own food

  3. Two Kingdoms of Bacteria: (Based on differences in structure of DNA, cell wall and cell membrane) Eubacteria and Archaebacteria

  4. Where are archaebacteria found? In Extreme Environments “Archae” Means Ancient • Geysers • Nuclear Reactors • Volcanoes • Ocean Floor Vents

  5. O2 Some are anaerobic, which means they can survive withoutOXYGEN.

  6. Eubacteria • “Eu” (True) • Live almost everywhere • Fresh and salt water • Land • In Humans E.coli

  7. Most are unicellular (single celled). Few live in clusters or groups.

  8. Most bacteria get their food by eating other things. They are consideredHeterotrophs.

  9. Bacteria have cell walls made of peptidoglycan

  10. Identification(based on shapes, cell walls, or movement) • Shapes: • Bacilli = rods • Cocci = round • Spirilla = spiral

  11. BACILLI (RODS)

  12. COCCI (ROUND)

  13. SPIRILLI (SPIRAL)

  14. A • Prefixes: • Diplo = 2 (pairs) • Strepto = chain • Staphylo = clumps B C

  15. Bacilli Spirilli Cocci

  16. Diplobaccillus

  17. Streptococcus Diplobacillus

  18. More Identification • Gram Staining is used to identify bacteria with extra membranes. These bacteria are more resistant to damage. • Gram + stain purple • Gram – (extra membrane) stain red

  19. Even More Identification MOVEMENT: • Flagella • Glide on slime • Wiggle • None

  20. How do bacteria move? Some have a flagellum.

  21. Others develop endospores and float through the air.

  22. Roles • Symbiotic relationship – E.coli in the intestines aid in digestion in exchange for food and a warm home.

  23. Recycle Chemicals • Decomposers • Oil-eating bacteria • Break-down raw sewage • Nitrogen-fixation: change nitrogen to a form that producers can use to make protein.

  24. buttermilk Many fermented foods are produced with the help of bacteria. • Cheese • Buttermilk • Sour cream • Vinegar • Pickles • Sauerkraut • Sourdough bread

  25. Pathogen:Disease-causing Agent • Bacteria cause disease in 2 ways: • Damage cells • Release toxins (poisons) Anthrax Acne

  26. Some bacteria cause diseases like…

  27. Anthrax Bacillus anthracis

  28. Strep Throat Streptococcus Food Poisoning Bacillus cereus

  29. Diarrhea, urinary tract infections Escherichia coli

  30. BACTERIAL DISEASES

  31. Bacteria reproduce through mitosis. In bacteria it is called binary fission.

  32. Binary fission is the same thing as mitosis. Binary fission is asexual reproduction sexual reproduction or

  33. Bacteria can also swap or pass on their genetic information without dividing. This is called … Conjugation

  34. Control • Antibiotics: medicines that stop bacterial growth • Sterilization: heat or disinfectant • Cook food all the way

  35. When bacteria are grown in a lab, it is called a Culture

  36. Petri dish Colony Agar

  37. 1 • 4 Control

  38. Zone of Inhibition • 1 • 4

  39. Virus Latin for “poison” A virus is a particle that can only be seen with an electron microscope.

  40. Viruses are not cells and are not made-up of cells. They don’t… • Contain a nucleus or cytoplasm • Eat • Grow • Carry on respiration • Or perform other biological functions

  41. A virus is surrounded by a capsid (protein coat) which determines the shape of the virus. The capsid contains nucleic acids (either DNA or RNA). Tail fibers for attachment to host cell.

  42. Viruses are classified by: • type of host cell • presence of DNA or RNA (retroviruses) • shape: Binal Polyhedral Filo

  43. VIRAL REPLICATION Viruses replicate in one of two ways: • Lytic • Lysogenic

  44. LYTIC CYCLE Virus attaches to host cell. Virus injects its DNA Cell lyses (breaks apart) and new viruses are released Virus DNA commands host cell to make new viral parts New viral parts assembled

  45. LYSOGENICCYCLE http://www.howstuffworks.com/virus-human2.htm

  46. LYSOGENIC CYCLE • Does not begin immediately • Viral DNA (called a prophage) attaches to the host cell’s chromosomes – lies dormant. • Environmental stimulus sends viral DNA into lytic cycle.

  47. VIRAL DISEASES

  48. VIRUS Ebola

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