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22 Cards in this Set

  • Front
  • Back
Importance of microbes in soil
part of carbon cycling- soil is largest active pool of organic matter. soil microbes can make either co2 or fossil fuels.
carbon sequestation
conversion of co2 to organic material
organic matter burial
makes fssil fuels and oil and coal
results of fossil fuel burning
an increase in atmospheric co2, increase in global temperature
results of global warming
an ice free artic, extreme weather, mass extinction, increase in diseases, human climate migration
steps of carbon cycle
outer- fossil fuels used by humans to make co2 which goes into ocean to make fossil fuels
co2 can go into land plants to microbes to fossil buels
microbes can make co2
Nitrogen Fixation
the convesion of nitrogen gas into ammonia- only bacteria can convert nitrogen to bioavaliable form and requires enzyme nitrinogase
atmospheric nitrogen versus nitrogen in cells
atmos- 70%, cells 9-15%
complex enzyme that requires a lot of energy. makes ammonia which is needed for proteins and dna.
nitrogen fixing bacteria
live independtly, can live in aerobic envionrments because of heterocyte
example: cyanobacteria
nitrogen fixing bacteria
steps in nitrogen cycle
n2- nitrogen fixing-(decomposition)--> organic n-- (ammonifaction)--ammonia- (nitrification)--> nitrate- (denitrification)-- > N2
plant associated nitrogen fixers
symbiotic mutualistic relationship with plants. plants give anaerobic environment and nutirients while prokaryotes supples fixed nitrogen. example- rhizobium
rhizobium- distorted form of bacteria inside nodule
organic N decays in plants to ammonia.
uses of ammonia
can be used in plants, aniamls, microbes- protein, dna, fungal cell walls. may also be used by ammonia oxidixing bacteria and archae in nitritifaction
ammonia converts to nitrate- carried out by ammonia oxidizer and nitrite oxidizers
ammonia oxidizers
take part in nitritication (ammonia to nitrate). chemolithoautotrophs
nitrite oxidizers
part of nitritication- nitrite to nitrate. chemolitotroph
fates of nitrate
1. can be used by plants and microbes to build dna and protein
2. can lead to denitrification
3. can be leached into waterways
nitrate to n2 gas. carried out by various bac and fungi. under anaerobic conditions. wetlands and riparian
nitrogen pollution
due to fertilizer
1. water contamination
2. autrophication
3. loss of diversity
4. n depostion