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10 Cards in this Set
- Front
- Back
- 3rd side (hint)
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Nitrogen Fixation |
- N2 to NH4 - Key Enzyme: -- Nitrogenase -- Dinitrogenase -- Dinitrogenase reductase Cyanobacteria, Anabaena, Rhizobia, Azorhizobium - heterocycts, spatial and temporal separation, alpha ketoglutarate, PatS |
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Rhizobia |
1) Recognition - plants produce flavonoids - chemoattractants for bacteria 2) Invasion - nod factors stimulate root hair - infection thread 3) Differentiation of bacterial and plant cells - O2 levels controlled by leghemoglobin - bacteria become bacteroids |
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Nitrification: ammonia oxidizing bacteria (amo) NH4+ -> NO2- |
Beta, gamma proteobacteria - NH3 + O2 -> NO2 + H2O - Key Enzyme: -- Ammonia Monooxygenase O2 is a substrate Evolutionary related to MMO -- hydroxylamine oxidoreductase |
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Nitrification: Nitride Oxidizing Bacteria |
Alpha, beta, sigma proteobacteria NO2- -> NO3- Key Enzymes: -- Nitrite Oxidoreductase e- reduce O2 through the ETC, H+ are pumped, generating PMF and ATP |
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Nitrification: Comammox |
Complete ammonia oxidation Nitrospira and Beta proteobacterium Key Enzymes: -- ammonia monoxygenase -- hydroxylamine oxidoreductase -- nitrite oxidoreductase |
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Ammonia oxidizing archaea |
Nitrosopumilus Found in oceans Aerobic oxidation |
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Anammox Anaerobic ammonia oxidation |
NH4+ + NO2 -> N2 + H2O |
Planctomycetes NO2- is e acceptor Pirellulosome - membrane bound structure containing nucleoid, ribosomes, other cytoplasmic components - ammoxosome compartment: holds hydrazine. Made of ladderanes Key Enzymes: -- nitrite reducing enzyme -- hydrazine dehydrogenase -- hydrazine dehydrogenase |
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Nitrate respiration |
Membrane bound/ periplasmic enzymes to couple subtrate level phosphorylation to nitrate reduction --> PMF Key Enzyme: Nitrate reductase Genes can only be expressed anaerobically |
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Assimilatory Nitrate Reduction |
NO3- --> NH4+ Key Enzyme: Nitrate and Nitrite reductase Anaerobic |
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Denitrification and Anamox |
Detrimental to agriculture Birth defects Both together: Converts NO3- --> N2 gas |
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