Chapter 18.1 Structure and Function
Bacteria Chapter 18.1 Structure and Function Earliest Prokaryotes (FYI)
Most numerous organisms on Earth Include all bacteria Earliest fossils date 2.5 billion years old 1. Prokaryotes microorganisms, lack nucleus, single cell
a. Monera old kingdom b. divided into 2 domains: archaea and bacteria c. kingdoms Eubacteria and Archaebacteria 2. Cell wall different in two domains
Eubacteria cell walls have peptidoglycan Archebacteria cell walls lack peptidoglycan, extreme environments, many anaerobic Methanogens Live in anaerobic environments (no oxygen)
Found in swamps, sewage treatment plants, digestive tracts of animals Extreme Halophiles Live in very salty water
Use salt to generate ATP (energy) Dead Sea, Great Salt Lake inhabitants Thermoacidophiles or Thermophiles
Live in extremely hot environments Found in volcanic vents, hot springs, cracks on ocean floor that leak acid Kingdom Eubacteria True Bacteria Characteristics 3 basic shapes (coccus, bacillus, spirilla)
Most are heterotrophic (cant make their own food) May be aerobic or anaerobic Identified by Gram staining Shapes Are Used to Classify
Coccus: Spherical (round) Vibrio: Comma shaped with flagella Bacillus: Rod shaped Spirillum: Spiral shape Spirochete: wormlike spiral shape Identified by arrangement
Strepto long chains Staphlo grapelike clusters Diplo pairs Diplococcus Streptococcus Causes Strep Throat Staphylococcus Bacterial 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 Gram Positive Bacteria (FYI)
Lactobacilli (makes yogurt & buttermilk) Actinomycetes (make antibiotics) Clostridium (lockjaw bacteria) Streptococcus (strep throat) Staphylococcus (staph infections) Gram Negative Rhizobacteria grow in root nodules of legumes (soybeans, peanuts) Fix N2 from air into usable ammonia Gram Negative Rickettsiae are parasitic bacteria carried by ticks
Cause Lyme disease & Rocky Mountain Spotted Fever Bacteria in Nature 1. Decomposers recycles nutrients
a. sewage treatment breakdown complex substances 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 Brainpop movie 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. 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 Useful Bacteria Some bacteria can degrade oil
Used to clean up oil spills Useful Bacteria Other uses for bacteria include making yogurt, cheese, and buttermilk. Making cheese, 3.5 minutes video\cheese, Milking_the_Cow.wmv Making cheese, 4 minutes video\cheese, churning.wmv 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