APES 1.5 Notes - The Nitrogen Cycle

nitrogen cycle

the movement of atoms and molecules containing nitrogen between sources and sinks

short

does nitrogen stay in reservoirs for a relatively long or short period of time?

nitrogen fixation

the process in which atmospheric nitrogen is converted into a form of nitrogen (mainly ammonia) that is available for uptake by plants and that can be synthesized into plant tissue

atmosphere

what is the major reservoir for nitrogen?

78%

approximately how much of earth's nitrogen is held in the atmosphere?

no

can humans use nitrogen that is in a gaseous state?

food (primarily in the form of proteins)

where do humans obtain their nitrogen from?

lightning, bacteria, cyanobacteria

what 3 things can carry out nitrogen fixation?

cyanobacteria

what type of bacteria can carry out photosynthesis?

denitrifying bacteria

what type of bacteria can carry out denitrification?

nitrification

soil bacteria change ammonia and ammonium ions to nitrate ions (NO3-)

soil bacteria

what type of bacteria can carry out nitrification?

denitrification

conversion of nitrates into nitrogen gas