Ch27 Bacteria & Archaea

  1. Domain Archaea
    • Prokaryotic-Lack nucleus
    • More resistant to heat and other extreme
    • Found in moderate conditions
  2. Extremophiles
    • Occupy habitats with very high salt content, acidity or methane levelsm or high temperatures.
    • Methanopyrus grows in deep sea thermal vents at 98 C-Hyperthermophile
    • Sulfolobus grows in hot springs at pH 3
    • Halophiles
  3. Domain Bacteria
    • 50 or so bacterial phyla-Structural and metabolic features of half unknown
    • Some are extremeophiles but many more bacteria favor moderate conditions
    • Form symbiotic relationships with eukaryotes
  4. Cyanobacteria
    • Photosynthetic bacteria abundant in fresh waters, oceans and wetlands and on surface of arid soils
    • Named for blue-green (cyan) color
    • Only prokaryotes that generate
    • Gave rise to plastids of eukaryotic algae and plants
    • Display greates structual diversity found among bacterial phyla
    • Essential ecological roles in producing organic carbon and fixing nitrogen
  5. Eukaryotic nucleus and cytoplasm
    likely arose in an ancient archaeal organism
  6. Mitochandria and plastids
    orginated from proteobacteria and cyanobacteria by endosymbiosis
  7. Bacteria and Archaea
    • Share small size, rapid growth and simple cellular structure
    • Are 1-5um in diameter
    • limits the amt of materials that can be stored within cells but allows faster cell division
  8. What are the five major shapes?
    • Spheres- cocci
    • Rods- bacilli
    • Comma-Shaped- vibrios
    • Spiral-shaped Spirochaetes r flexible & spirilli r rigid

    Some occur as single cells, pairs and filaments
  9. Mucilage
    • Sometimes called Glycocalyx
    • Composed of polysacc., protein or both
    • Secreted from cells

    • Fxn: Evade host defenses
    • Hold colony together
  10. Cell-Wall Structure
    • Most hv rigid cell wall outside the PM
    • Maintain cell shape and help protect agant attack
    • Help to avoid lysis in hypotonic soltion

    Archaea and some bacteria use protein where as most bacteria use peptidoglycan
  11. What is gram positive?
    • Thick peptidoglycan layer
    • Purple dye held in thick layer
    • Cells are stained purple
    • Vulnerable to pencillin that interferes in cell wall synethesis
  12. What is gram negative?
    • Less peptidoglycan and a thin outer envelope of lipopolysac.
    • Lose purple stain but retain final pink stain
    • Cells are stained pink
    • Resists pencillin and requires other antibios'
  13. What is their motility?
    • Move to favorable conditions
    • Respond to chemical signals

    Switch, twitch, glide or adjust floatation
  14. What is Flagella?
    • Swimming
    • Different in eukaryotic flagella
    • Like an outboard boat motor
    • Differ in number and location of flagella
  15. What is Pili?
    • Twitch or glide across surface
    • Threadlike cell surface structures
    • Play import roles in bacterial reprod and dz processes
  16. What is binary fusion?
    divide by splitting in two
  17. What is Akinetes?
    • Found in aquatic filamentous cyanbact
    • Develop when winter approaches
    • Survive winter and produce new filaments in spring
  18. What is Endospores?
    • Tough protein coat
    • Amazingly long dormant span
    • Found in some Gram-pos bacteria

    IE: Bacillus antracis, Clostridium botulinum, Clostridium tetani
  19. How they obtain their genetic material?
    • Transduction: Via viral vector
    • Transformation: Via uptake of DNA from environment
    • Conjugation: Via mating with another cell
  20. What is Autotrophs?
    Produce all or most of their own organic compounds
  21. What is Photoautotroph?
    Use light as energy source for synthesis of organic compds frm CO2 or H2S.
  22. What is Chemoautotrophs?
    Use energy obtained from chemical modification of inorganic compds to synthesize organic compds
  23. What is Heterotrophs?
    Organisms that require at least one organic compd and often more
  24. What is Photoheterotroph?
    Able to use light energy to make ATP but they must take in organic compds from the envirnmt
  25. What is Chemoorgantroph?
    Must obtain organic molecules for both energy and carbon source.
  26. What is Obligate?
    Require oxygen
  27. What is Facultative aerobes?
    can use oxygen or not
  28. What is Obligate Anaerobes?
    cannot tolerate oxygen
  29. What is Aeortorlerant anaerobes?
    Do not use oxygen but are not poisoned by it
  30. What is envoles of Carbon cycle?
    • Producers synthesize organic compds used by other organisms as food
    • Decomposers break down dead organisms to release minerals for reuse
    • Methanogens-makes methane
    • Methanotrophs- consume methane
  31. What is Symbosis
    An organism that lives in close association with one or more other organisms
  32. What is Parasitism?
    One partner benefits at the expense of the other
  33. What is Mutualism?
    Association beneficial to both partners
  34. What is Syntrophy?
    Some bacteria live together and supply each other with essential nutrients
  35. What is Consortia?
    Larger community of nutrient exchangers.

    IE: Marine worm with no mouth, gut, or anus depends on bacteria inside it for food and waste recycyling
  36. Associations with Eukaryotes
    • Bacteria induces normal development in Ulva
    • Bioluminescent bacteria in squid and other animals
Card Set
Ch27 Bacteria & Archaea