mb 230 4-1

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  1. 3 global cycles
    • 1) nitrogen cycle
    • 2) Carbon cycle
    • 3) Sulfur cycle
  2. which 4 biological molecules use nitrogen
    • 1)amino acids
    • 2)nucleic acids
    • 3) enzymes
    • 4) vitamins
  3. _____ ____ converts organic nitrogen gas into organic nitrogen.
    nitrogen fixation
  4. ____ converts organic nitrogen into ammonia
  5. % of the nitrogen gas into atmosphere is
  6. ____ converts ammonia into nitrate
  7. ____ converts nitrates into nitrogen gas
  8. 4 steps in nitrogen cycle
    • 1) nitrogen fixation
    • 2) ammonification
    • 3) nitrification then nitrate
    • 4) denitrification
  9. What enzyme does nitrogen fixation require
  10. Nitrogenase uses a lot of ___  and ___ to convert a single Nmolecules into organic nitrogen
    ATP energy and electrons
  11. ___ needs an anaerobic environment, so oxygen interferes with it
  12. only bacteria have___
  13. ____ bacteria are free-living nitrogen-fixing bacteria
  14. free living nitrogen-fixing bacteria: ___ have specialized ____. 

    Specialized cells in ____ create a microenvironment where nitrogen fixation can take place on called ____
    cyanobacteria, heterocysts have specialized membranes.

    Cyanobacteria, heterocytes
  15. most cells in cyanobacteria perform
    photosynthesis and respiration, except heterocysts.
  16. photolithoautotrophic free-living nitrogen fixation bacteria are called _____, and require ____for respiration
    cyanobacteria, require oxygen
  17. Name a nitrogen-fixation chemoheterotrophic bacteria that live in an anaerobic environment on root nodules.
    Rhizobium Spp
  18. Rhizobium form a ____ symbiotic relationship with plants
  19. Rhizobium spp are (aerobic or anaerobic) bacteria which live in an (aerobic or anaerobic) environment on the root nodules in the plant
    aerobic bacteria that live in anaerobic environment.
  20. Plant supplies oxygen to bacteria in a controlled way through ____, so it will not interfere with nitrogenase
    Legume hemoblobin (leghemoglobin) carries oxygen to bacteria from plant, which prevents nitrogenase from coming in contact with oxygen.
  21. ___ is toxic to many things at high concentration, so what cycle quickly follows?
    Ammonia, nitrification converts ammonia to nitrite.
  22. 2 steps in nitrification
    • 1st step: ammonia oxydation
    • 2nd step: nitrite oxydation
  23. 1)ammonia oxidation converts
    2)Nitrite oxidation converts
    • 1)bacteria converts ammonia into nitrite
    • 2) bacteria converts nitrite (food) into nitrate (waste)
  24. What process?
    -an anaerobic process which offen occurs in wetlands and other riparian (water) regions and waste water treatment facilities.
    -This process can become overwhelmed if there is a large amount of nitrates in the environment (e.g. from fertilizer usage).
  25. Nitrate leaching is another name for
  26. What is the result of nitrate leaching? example
    • excess of nitrates cause algae bloom,
    • followed by bacterial bloom which causes loss of oxygen in water and death of plants and animals in/near water.
    • (example Red Tide).
  27. Eutrophication is the
    excess of nitrate causing algae bloom, followed by bacterial bloom, loss of oxygen and death of plants and animals
  28. How do carbon atoms become accessible to living atoms through the carbon cycle?
    photosynthetic plants in ocean and on land convert inorganic carbon into organic carbon.
  29. Both routs of converting inorganic carbon into organic carbon rely on ____
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mb 230 4-1
2015-03-09 01:25:35
mb 230
mb 230 4-1
mb 230 4-1
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