1. Chapter 18.1 Structure and Function
Bacteria
Chapter 18.1
Structure and Function

2. Earliest Prokaryotes (FYI)
Most numerous organisms on Earth
Include all bacteria
Earliest fossils date 2.5 billion years old

4. 1. Prokaryotes microorganisms, lack nucleus, single cell
a. Monera old kingdom
b. divided into 2 domains: archaea and bacteria
c. kingdoms Eubacteria and Archaebacteria

5. 2. Cell wall different in two domains
Eubacteria cell walls have peptidoglycan
Archebacteria cell walls lack peptidoglycan, extreme environments, many anaerobic

6. Methanogens Live in anaerobic environments (no oxygen)
Found in swamps, sewage treatment plants, digestive tracts of animals

7. Extreme Halophiles Live in very salty water
Use salt to generate ATP (energy)
Dead Sea, Great Salt Lake inhabitants

8. Thermoacidophiles or Thermophiles
Live in extremely hot environments
Found in volcanic vents, hot springs, cracks on ocean floor that leak acid

9. Kingdom Eubacteria
True Bacteria

10. Characteristics 3 basic shapes (coccus, bacillus, spirilla)
Most are heterotrophic (can’t make their own food)
May be aerobic or anaerobic
Identified by Gram staining

11. Shapes Are Used to Classify
Coccus: Spherical (round)
Vibrio: Comma shaped with flagella
Bacillus: Rod shaped
Spirillum: Spiral shape
Spirochete: wormlike spiral shape

15. Identified by arrangement
Strepto long chains
Staphlo grapelike clusters
Diplo pairs

18. Diplococcus

19. Streptococcus Causes Strep Throat

21. Staphylococcus Bacterial

22. Identified gram stains
Gram stains dyes used to stain cells
If pink gram negative
Thin layer of peptidoglycan
Hard to treat with antibiotics
If violet gram positive
Thick layer of peptidoglycan
Can be treated with antibiotics

23. Gram Positive Bacteria (FYI)
Lactobacilli (makes yogurt & buttermilk)
Actinomycetes (make antibiotics)
Clostridium (lockjaw bacteria)
Streptococcus (strep throat)
Staphylococcus (staph infections)

24. Gram Negative
Rhizobacteria grow in root nodules of legumes (soybeans, peanuts)
Fix N2 from air into usable ammonia

25. Gram Negative Rickettsiae are parasitic bacteria carried by ticks
Cause Lyme disease & Rocky Mountain Spotted Fever

28. Bacteria in Nature

29. 1. Decomposers– recycles nutrients
a. sewage treatment  breakdown complex substances

30. 2. Nitrogen fixation
a. bacteria grow on knobs, nodules, on roots of certain plants. Convert Nitrogen gas into ammonia, a nitrogen form usable by plants
b. Nitrogen needed for amino acids, amine group NH2

31. Brainpop movie

32. 3. Diseases
a. damage tissue: tuberculosis (lungs), strept throat, Pneumonia, typhoid, cholera, tooth decay
b. release toxins
c. treatment: vaccines and antibiotics
Antibiotics accidentally discovered by Fleming in A fungus, Penicilium, contaminated a bacterial culture. Fungus produces a chemical that inhibited the bacteria penicillin.

33. 4. Human uses b. digest petroleum in oil spills
a. cheese, yogurt, buttermilk, sour cream, pickles, vinegar
b. digest petroleum in oil spills
c. synthesize drugs in bioengineering

34. Useful Bacteria Some bacteria can degrade oil
Used to clean up oil spills

35. Useful Bacteria
Other uses for bacteria include making yogurt, cheese, and buttermilk.

36. Making cheese, 3.5 minutes
video\cheese, Milking_the_Cow.wmv

37. Making cheese, 4 minutes
video\cheese, churning.wmv

38. 5. Controlling bacteria
a. Sterilization great heat or chemicals used to destroy bacteria
b. disinfectants a chemical solution kills bacteria; used in hospitals, homes (bathrooms and kitchens)
c. refrigeration bacteria are slowed down
d. canning (heat); salt, vinegar, or sugar