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2011-10-09 20:27:34

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  1. Gram positive vs gram negative vs archaea?
    • Gram positive: Will stain with crystal violet dye, thick wall made of peptidoglycan
    • Gram negative: Will not stain with crystal violet dye, thin wall of peptidoglycan surrounded by additional
    • Archaea cell walls do not contain peptidoglycan
  2. 3 “structures” of bacteria with brief function
    • Fimbriae: short, spikey “hairs” that provide anchorage
    • Flagella: movement for cell, different than eukaryotic flagella
    • Pili: Bridge connecting two bacteria for conjugation
  3. 3 shapes?
    • Bacillus: stick
    • Coccus: sphere
    • Spirillum: squiggly/spiral
  4. Cyanobacteria evolutionary/ecological imp.
    • Ecological: Involved in carbon cycle (photosynthesis) and nitrogen cycle (N-fixation)
    • Evolutionary: believed to be precursor to chloroplasts in eukaryotes. Major group that changed the earth’s atmosphere.
  5. Cyanobacteria photosynthesis information.
    • Use chlorophyll a and b + unique accessory pigments called PHYCOBOILINS [phycoerythrin and phycocyanin]
    • Thykaloids: photosynthetic membrane layers similar to plants
  6. Types of cyanobacteria anatomy with vague description
    • Filamentous: collection of bacteria cells that DON’T SEPARATE after binary fission
    • -hormogonia are broken filaments that may start a new filament strand
    • Colonial: secrete mucilaginious sheath to bind cells together
  7. What’s a stromatolite?
    • Stacked pattern of Ca2+ rich sediment created by cyanobacteria.
    • Lime extracted from H2O and secreted around the filaments caused their creation
  8. Describe cyanobacterial blooms
    Part of Plankton (basis of food chain), but can explode in # (a bloom / red tide), and can release toxic compounds which affect the food chain.
  9. In cyanobacteria where does N-fixation occur? What is the “endospore-like” cell called?
    • Heterocysts are specialized cells that carry enzymes for N-fixation. VERY THICK WALL and darker center.
    • Akinetes are “hibernating” cells that form in response to a harsh env. BIG OVAL CELLS.
  10. 2 Given endosymbyotic relationships
    • Azolla can complex w/ cyanos for N-fixation
    • Lichens are ½ cyano and ½ fungi