BIOL2142 Lecture Notes - Lecture 7: Nitrogen Cycle, Denitrification, Electron Acceptor
Document Summary
Eutrophication: too much nutrients in water, breaks down the ecosystem - increase in algal blooms. Nitrates and nitrites get denitrified into nitrogen gas and nitrous oxide. Chemolithotrophs: energy source and electron source both from inorganic molecules. Denitrification - using nitrate as an electron acceptor in anaerobic respiration. Just use the nitrate as an electron acceptor. During aerobic respiration, oxygen is used as the terminal electron acceptor. During anaerobic respiration, some organisms use other electron acceptors, e. g. sulfate, nitrate, co2, fe3+ Nitrate is good because it is fairly oxidised. Cyt c, cyt d1 - to nitrous oxide. Doesn"t always further convert probably sue to no being a gas, so it just floats away. Difference in redox potentials between nad+/nadh and no3-/n2 is smaller than the difference between nad+/nadh and o2/h2o. This makes n better available for crop plants. Very diverse chemolithoautotrophs, aerobic nitrification gain electrons from oxidation of ammonium to nitrate or nitrite nitrite further oxidized to nitrate.
