Bacteria and Archaea

  1. Biofilms
    complex and highly organized microbial communities consisting of layers of microbial cells associated with physical surfaces
  2. process of biofilms
    • individual cells populate the surface
    • eps is produced and attached becomes irreversible
    • biofilm architecture develops and matures
    • single cells are released from biofilm
  3. Aerobic organisms live top or bottom?
    Top for oxygen
  4. Example of biofilms
    slime-encased aggregations of microbes
  5. benefit of forming a biofilm?
    • Increased protection from harmful agents (antibodies), antibiotics and uv radiation
    • Increased access to nutrients and the removal of toxic waste
    • Increased genetic diversity (dna from one organism may be taken up by another when dead)
  6. Where do they grow
    Syringes and other places
  7. Clinical significance
    Biofilms can cause persistent infections, that can be fatal (on catheters or surgically implanted or on exposed skin of burn victims)
  8. Qyoroum sensing
    Cell to cell communication to determine their cell size.
  9. Name of molecules in quorum sensing
    • autoinducers
    • made only by Gram negative bacteria
    • in ahl1
    • ahl2 by both gram
    • oligopeptides produced by gram positive
    • A-factor (filamentous gram-positive bacteria Streptomyces griseus)
    • Hydroxy-alkyl-quinoline (pseudomonas aeruginosa
  10. Obligate parasites
    • can only live inside host cells.
    • ¬†Chlamydia
  11. Sporulation
    • Bacteria
    • Fungi
    • Protozoa
  12. Bacteria
    make asexual spores; limited to only a small number of spcies
  13. Fungi
    produce sexual and asexual spores
  14. Protozoa
    • produce asexual spores
    • apicomplexans
  15. Bacterial spores are called...
    • Endospores
    • Develop inside vegetative bacterial cells
  16. Endospores do what
    help bacteria survive harsh conditions
  17. gram p bacilli
    make spores
  18. Binary fission
    division, doubling, generation
  19. Growth under advers conditions
    • Bacterial endospores
    • fungal spores
    • protozoan spores
    • protozoan cysts
    • parasitic worms
  20. What are the four stages of cell growth in a closed environment
    Lag phase....
  21. is lag phase occuring in binary fission
  22. Exponential growth/log phase
    geometrical increase in population size
  23. stationary phase and death phase
Card Set
Bacteria and Archaea