1. Introduction

Card Set Information

1. Introduction
2011-10-02 23:32:12
PMB 112 midterm1

general microbiology lecture 1
Show Answers:

  1. microorganisms
    • a diverse group of organisms that exist as free-living single cells or cell clusters
    • single cell can live outside of other cells
    • includes algae/fungi/protist, bacteria, archaea
  2. Robert Hooke
    • built compound microscope
    • saw and documented microorganisms
    • coined the term cells from viewing cork
  3. Anton van Leeuwenhoek
    • had simple better lens with better magnification
    • first recorded observation of bacteria
  4. Louis Pasteur
    • disproved spontaneous generation with swan-neck flask experiment - showed microbes come only from pre-existing microbes
    • studied fermentations and isolated microorganisms responsible for fermentations
  5. swan neck flask experiment
    • nonsterile liquid put in flask, neck drawn out, sterilize
    • MO trapped in bend, remained sterile for years
    • flask tipped, MO grow in culture
  6. Pasteur's fermentation observations
    • need specific microbes for specific fermentation
    • complex organic compounds present
    • some compounds present were stereospecific
  7. Robert Koch
    pioneered pure cultures on solid medium to grow individual colonies
  8. Semmelweiss, Pasteur, Lister
    • came up with germ theory in response to miasma theory
    • encouraged antiseptic practices - washing hands/instruments to prevent spread of germs
  9. Koch's postulates
    • established framework for showing that a disease is caused by a microorganism
    • 1) the suspected organism should be present in all cases of disease and absent from healthy individuals
    • 2) the suspected organism should be isolated form a diseased individual and grown in pure culture
    • 3) organisms from pure culture should cause disease in healthy individual
    • 4) organism should be reisolated and shown to be same as original
  10. cases that do not satisfy Koch's postulates
    • disease caused by microbe that is present in normal individuals
    • organism can't be grown in culture
    • no animal model
  11. Martinus Beijernick
    • enrichment culture
    • selective culture medium favor growth of specific organisms
  12. Beijernick and Winogradsky
    • idea of microorganisms as biogeochemical agents
    • isolated bacteria with specific properties using enrichment cultures
  13. autotrophs
    acquire carbon from air
  14. chemolithotrophs
    gain energy from oxidation of inorganic compounds
  15. nitrogen fixing bacteria
    convert N2 in the air to to NH3, which can be used
  16. bacteria and metabolism
    • bacteria have far greater metabolic diversity
    • can live on earth without plants and animals, reverse not true
    • nitrogen cycle depends on bacteria - perform nitrogen fixation and nitrification