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