1.5 - Nitrogen Cycle

Question 1

Nitrogen cycle

Answer 1

the movement of nitrogen containing molecules between sources and sinks/reservoirs; main reservoir is atmosphere

Question 2

Nitrogen fixation

Answer 2

N2 converted into NH3 (ammonia) or NO3- (nitrate)

Question 3

Bacterial fixation

Answer 3

Certain bacteria that live in soil/in symbiotic relationships with plant root nodules convert N2 into ammonia (NH3)

Question 4

Legumes

Answer 4

peas, beans, etc. attract bacteria to fix nitrogen for them

Question 5

Synthetic fixation

Answer 5

humans combust fossil fuels to convert N2 into NO3- (nitrate)

Question 6

Assimilation

Answer 6

plants and animals taking in Nitrogen and incorporating it into their body; in amino acids, proteins, nucleic acids, dna, etc.

Question 7

Ammonification

Answer 7

soil bacteria, microbes, and decomposes, convert waste/dead biomass back into NH3, reuniting it into the soil

Question 8

Nitrification

Answer 8

conversion of NH4 into NO2- (nitrite) then NO3- (nitrate) by soil bacteria

Question 9

Denitrification

Answer 9

conversion of soil nitrogen (NO3-) into nitrous oxide (N2O) which returns to the atmosphere

Question 10

Leaching & eutrophication

Answer 10

synthetic fertilizers use leads to NO3- (nitrates) leaching or being carried out of soil by water.

Question 11

Ammonia volatilization

Answer 11

excess fertilizer use can lead to NH3 gas entering the atmosphere