ch 11 flashcards.txt

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ch 11 flashcards.txt
2011-03-21 19:05:50


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  1. Chemolithotrophs
    Oxidize INORGANIC compounds to obtain ENERGY
  2. Chemoorganotrophs
    Oxidize ORGANIC compounds to obtain ENERGY
  3. Anaerobe
    Uses CO2 as its carbon source
  4. Anaerobic chemolithotrophs
    • Methanogens: OXIDIZE hydrogen gas to generate methane. Use CO2 as final e- acceptor
    • Ie: Euryarchaeota
    • Found in sewage, swamps, sensitive to oxygen
    • Used in bioremediation
  5. Anaerobic chemoorganotrophs � anaerobic respiration
    • Sulfur and sulfate reducing Bacteria: generate hydrogen SULFIDE, use Sulfate as final e- acceptor.
    • Ie: Proteobacteria
    • Gram NEG, Essential for sulfur cycle in ecosystem, responsible for rotten egg smell, found in organic matter
    • Rxn ie: Organic comp + S (final e-acceptor) -> CO2 + H2S (hydrogen sulfide)
  6. Anaerobic chemoorganotrophs � fermentative
    • ALL GRAM +
    • Clostridium: endospore forming obligate anaerobes
    • Lactic Acid Bacteria � Streptococcus: Lactic acid is major end product of Fermentation, energy only comes from Substrate level phosphorylation. Most can grow in aerobic environments
    • Ie for both above: FirmiCUTES
    • Propionibacterium: Propionic acid is major end product of fermentation. Swiss cheese
    • Ie: Actinobacteria
  7. Earliest organism of Oxygenic phototrophs
    Cyanobacteria: act to harvest sunlight to produce organic compounds thru conversion of CO2
  8. Anoxygenic phototrophs
    OXIDIZE hydrogen sulfide or ORGANIC molecules when making NADPH
  9. Oxygenic phototrophs
    Photosynthetic bacteria that use WATER as source of electrons. OXIDATION of H20 liberates Oxygen
  10. Anoxygenic phototrophs
    • Purple Sulfur bacteria (ie Chromatium): Use SULFUR compounds (prefer hydrogen sulfide) as a source of electrons when making reducing power. Ie- Proteobacteria
    • Purple Non-sulfur Bacteria (ie Rhodobacter): Use ORGANIC compounds as source of Electrons for reducing power. Found in soil, diverse metabolism. Ie- Proteobacteria
    • Green Sulfur bacteria (ie: Chlorobium): Found in habitats similar to purple sulfur bac. ALL are strict ANAEROBES. Ie- Chlorobi
    • Chloroflexus: Characterized by filamentous growth. Ie- Chloroflexi
    • Others: Heliobacterium- ie-firmicutes
  11. Oxygenic phototrophs
    • Nitrogen-fixing cyanobacteria: incorporate Nitrogen gas & CO2 into organic material to produce ammonia. Helps control CO2 atmosphere levels.
    • Occurs in HETEROCYST (protects breakdown of nitrogenase from oxygen)
  12. Aerobic chemolithotrophs
    • Obtain energy by OXIDIZING reduced inorganic chemicals.
    • These use oxygen as the final e- acceptor
    • Include sulfur-oxidizing bacteria, nitrifiers and hydrogen-oxidizing bacteria
  13. Aerobic chemoorganotrophs
    • OXIDIZE organic compounds to obtain energy
    • Use oxygen as final e- acceptor.
    • Can be classified as: Obligate aerobes or facultative anaerobes
    • Ie: Organic compound + O2 -> CO2 + H20
  14. Aerobic chemolithotrophs
    • All seen with Proteobacteria (exceptHYDROGEN oxidizing bacteria, ie is Aquafacae)
    • Sulfur-Oxidizing bacteria (ie- Beggiatoa): OXIDIZE reduced sulfur components, sulfuric acid is produced. Ie- S + O2 -> H2SO4 + H20. Live in sulfur springs, cause bulking in sewage treatment.
    • Unicellular Sulfur Oxidizers (Thiobacillus): same as above, but some produce enough acid to lower pH to 1.0.
    • Nitrifiers (ie- Nitrococcus): OXIDIZE inorganic nitrogen (such as ammoniam(NH4) or Nitrite(NO2)) to obtain ENERGY. Ie- NH4 + O2 -> NO2 + H20 + H
    • These deplete O2 in waters that are contaminated with ammonia waste
    • Hydrogen Oxidizing Bacteria (ie- Aquifex): Obligate Chemolithotrophs, found in HOT springs. Ie- H2 + O2 -> H20
  15. Aerobic chemoorganotrophs (OBLIGATE Aerobes)
    • OBLIGATE Aerobes (ONLY Aerobic respiration)
    • Micrococcus: Gram + in soil. Ie- Actinobacteria
    • Mycobacterium (TB): Gram +, lives on DEAD or decaying matter. Ie- Actinobacteria
    • Pseudomonas: Gram Neg, motile and pigmented, opportunistic. Ie- Proteobacteria
    • Thermus: produces Taq. Ie- Deinococcus-Thermus
    • Deinococcus: used to cleanup Radioactive contamination Ie- Deinococcus-Thermus
  16. Aerobic chemoorganotrophs (Facultative Anaerobes)
    • Corynebacterium: Gram + rods, inhabits soil, H20. Ie- Actinobacteria
    • Enterobacteriaceae (ie- E. coli): Gram neg rods, live in intestinal tract. Ie- Proteobacteria
  17. Example of a medically important terrestrial thriving chemoorganotroph
    Argobacterium: causes plant tumors, used by scientists to genetically modify plants to have higher crop yields. ie- (phylum is...Proteobacteria)
  18. Example of a medically important aquatic thriving chemoorganotroph
    Sheathed bacteria (Sphaerotilus): forms chains of cells enclosed within a protective sheath. ie- proteobacteria
  19. List the kinds of bacteria that Form endospores
    Clostridium (anaerobic chemoorganotroph): is a GRAM + rod
  20. List and describe the kinds of prokaryotic microorganisms that live in an aquatic environment.
    • Sulfur Oxidizing bacteria, Nitrifiers & hydrogen oxidizing bacteria (aerobic chemolithotroph)
    • Purple Sulfur and Non-sulfur bacteria (anoxygenic phototroph)
    • Methanogens (anaerobic chemolithotrophs)
    • Corynebacterium (aerobic chemoorganotrophs)
  21. List and describe the kinds of prokaryotic microorganisms that use animals as their habitat.
    • Methanogens: found in the digestive tract of mammal (anaerobic chemolithotrophs)
    • Enterobacteriaceae (ie- E. coli): Gram neg rods, live in intestinal tract
  22. List and describe the kinds of prokaryotic microorganisms that live under extreme conditions.
    Hydrogen-oxidizing bacteria (aerobic chemolithotrophs) can survive and thrive at 95 Celsius.