Biology unit 4 nitrogen cycle help?

hi, I have two books which are telling me two different things and it's stressing me out as I have the exam tomorrow.

Can someone clarify this and tell me if this is correct? I'm mainly confused with the role of nitrogen fixing.... One book tells me it only creates ammonia and the other tells me it creates nitrogen containing compounds? And is ammonia actually used by the plant for amino acids in nitrogen fixing mutualistic bacteria, or is ammonia used by the bacteria to first create proteins/amino acids and then exchange them with the plant?

Ammonification
when Ammonium containing compounds in dead organisms converted to ammonia/ammonium
ammonium containing compounds ----------> Ammonia/ammonium

Nitrification
Ammonia ------> Nitrites ------> Nitrates

Denitrification (Anaerobic conditions needed)
Nitrates ------> Nitrogen Gas

Nitrogen Fixing (by free-living bacteria)
Nitrogen Gas ---> Ammonia/ammonium --->amino acids ----> releases nitrogen containing compounds

-Nitrogen gas is converted into ammonia/ammonium.
-Ammonia is used to produce amino acids
-Once bacteria dies and decays, releases nitrogen containing compounds.

Nitrogen Fixing by mutualistic bacteria relationship with plants
-Nitrogen fixing bacteria in root nodules converts nitrogen gas into ammonia/ammonium
-Ammonia is used for synthesis of amino acids by bacteria
-Bacteria receives carbohydrates from plants and plants receive amino acids from exchange with bacteria

(edited 8 years ago)

Reply 1

task123

Nitrogen fixing takes place by both the free living and the mutualistic bacteria. The free living bacteria are the ones that fix nitrogen from the atmosphere and convert it into ammonium ions in the soils and then the mutualistic bacteria are the ones which use the nitrogen to makes the nitrogen containing compounds.

The mutalistic bacteria produces the amino acids themselves before exchanging them with the plant and in return it receives carbohydrates from the plant.

I hope this helps and I hope its right haha, good luck!

Reply 2

Bustamove

Original post by task123

thats what I'm confused with... one book tells me that in free living bacteria, nitrogen gas in atmosphere is converted to ammonium ions in soil and the other book tells me that in free living bacteria, nitrogen gas is converted to ammonia/ammonium used to produce amino acids, then dies and releases nitrogen containing compounds

Reply 3

task123

Original post by Bustamove

right ok i see, my book says that the free living bacteria reduce the nitrogen to ammonia which is released when it dies and decays so i think I will just go off that..sorry I really wasnt much help!

Reply 4

Bustamove

Original post by task123

right ok i see, my book says that the free living bacteria reduce the nitrogen to ammonia which is released when it dies and decays so i think I will just go off that..sorry I really wasnt much help!

Ah okay.. I see, i just needed some clarification. This explains it, one of my books just didn't explain it properly. So ammonia/nitrogen containing compounds is only released into the soil by free living nitrogen fixing bacteria when it dies.. Thank you :smile: