Nitrogen cycle Flashcards
What are the ways plants gain nitrogen
they can only get it in the form of ammonium or nitrate ions
so how do they actually get the nitrogen
through one of the 4 stages of the nitrogen cycle
what are the 4 stages of the nitrogen cycle
nitrogen fixation
nitrification
ammonification
de-nirification
What is nitrogen fixation
process that causes the strong two atom nitrogen molecules found in the atmosphere to break apart so they can combine with other atoms
How does nitrogen get fixed
when it is combined with oxygen or hydrogen
what are the 3 ways nitrogen can become fixed
atmospheric fixation (lightning)
industrial fixation
(haber process)
Biological fixation
How does atmospheric fixation occur (lightning)
the enormous energy of lightning breaks nitrogen molecules apart and enables the nitrogen atoms to combine with oxygen forming nitrogen oxides.
Nitrogen oxides then dissolve in rain which forms
nitrate ions
How does industrial fixation occur
under high pressure and temperature and with the use of a catalyst atmospheric nitrogen and hydrogen are combined to form ammonia or an ammonium ion
What are the 2 types of biological fixation
Free living bacteria (azotobacter)
Symbiotic relationship bacteria
rhizobium
What happens to ammonia stored in the soil
they travel through the second process of the nitrogen cycle called nitrification
What is nitrification
2 Step proccess
when an ammonia is converted to nitrite ion by NITROSOMONAS
that nitrite is converted to nitrate via nitrobacter
What type of reaction is nitrification
oxidation reactions
what type of bacteria is Nitrosomonas and Nitrobacter
Aerobic
What is ammonification
Decomposition by bacteria and fungi breaks down amino acids from dead animals and plants,
Faeces and urine and wastes back into ammonia or ammonium ion
How does nitrogen re enter the atmosphere
Denitrification
