found in protein, DNA, RNA in living things
78% of the atmosphere
Nitrogen must be ___ or changed into a usable form before plants can take it up and use it.
done by atmospheric lightning and certain bacteria on legume plant roots
bacteria that fix nitrogen
converting ammonia to nitrites then nitrates which are usable by plants
plant roots take up nitrogen-containing compounds and ions and use them to make proteins and DNA
specialized bacteria break down ammonia in dead organisms into ammonia and ammonium salts
specialized bacteria convert ammonia, etc. into nitrates and nitrites then into N2 gas.