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2013-05-30 15:04:58

chapter 7
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  1. nutrition
    process by which nutrients are acquired from environment and used for cellular activities
  2. nutrients
    chemical substance required for growth
  3. macronutrients
    required in large amount
  4. micronutrients
    required in small amount, includes trace elements
  5. growth factor
    organic compound that the organism can't synthesize, must be in diet; often vitamins or amino acids; called essential nutrients
  6. generation time
    time for a population to double, vary with conditions and by species
  7. prokaryotic reproduction
    by binary fission, cell elongates, chromosome replicates, and cell splits
  8. growth curve
    closed system, no nutrients added, waste isn't removed
  9. lag phase
    period to adjust, no net increase in population
  10. exponential (log) phase
    rapid growth in population; nutrients abundant and waste is minimal
  11. stationary phase
    no net increase in population, death rate = division; nutrients decreasing and waste is increasing
  12. death phase
    population dying off, conditions toxic due to waste, no nutrients left
  13. 5 physical factors that affect growth of prokaryotes
    • 1. temp
    • 2. oxygen
    • 3. pH
    • 4. osmostic pressure
    • 5. other factors (ex: barometric pressure)
  14. How does temp. affect the growth of prokaryotes?
    • every MO has an optimum growth temp.
    • a. psychrophiles - prefer cold (0-20'c)
    • b. mesophiles - prefer warmer (20-45'c), includes human pathogens
    • c. thermophiles - prefer hot (40-70'c)
  15. How does oxygen requirments affect prokaryotes growth?
    • aerobic
    • anaerobic
    • aerotolerant
    • microaerophiles
    • capnophiles
  16. aerobic
    • live in presence of O2
    • * obligate aerobe -require O2
    • * survive in prescence of O2
    •      a) superoxide dismutase
    •      b) catalase
  17. anaerobic
    • without O2
    • * obligate anaerobe - O2 kills them, lack the superoxide dismutase
    • * facultative anaerobe - can live with or without O2
  18. aerotolerant
    doesn't use O2, doesn't harm
  19. microaerophiles
    very small amounts of O2
  20. capnophiles
    high CO2, low O2
  21. pH requirements that affect growth of prokaryotes
    • acidophiles - live at pH < 7
    • alkalophiles - live at pH > 7
    • neutrophiles - live ~ pH 7
  22. Osmotic pressure affect on prokaryote growth
    • osmophiles- high osmotic pressure due to high solutes in medium. ex: sugars, salts, etc
    • halophile - high salt concentration
    • halotolerant or osmotolerant
  23. barometric pressure affect on prokaryote growth
    • barophiles - require increased pressure
    • barotolerant - can survive but don't prefer it
  24. symbiotic association between species
    • two species in same locale, interact
    • ex: mutualism, commensalism, parasitism
  25. mutualism
    both species benefit.  ex: vagina and lactobacillus.  keep pH low and yeast from growing
  26. commensalism
    commensal benefits with host unharmed
  27. parasitism
    parasite benefits and host is harmed
  28. nonsymbiotic association between species
    • synergism- combined efforts have a more positive outcome
    • antagonism - counteract each other
  29. autotrophs
    use CO2 as their carbon source
  30. photoautotrophs
    use light energy to use the CO2; photosynthesis
  31. chemoautotrophs
    use inorganic compounds for energy to use CO2
  32. heterotrophs
    use an organic compound for a carbon source
  33. chemoheterotrophs
    energy + carbon from organic compounds
  34. photoheterotrophs
    light energy + organic compounds for carbon