Nitrogen Cycle Flashcards
(11 cards)
How much of the air s composed of Nitrogen
78%
Why is nitrogen essential to life?
Because it is a key component of amino acids and nucleic acids. Even ATP contains nitrogen.
How do plants and animals get nitrogen?
Sense they can not obtain nitrogen directly from the atmosphere they must depend on a process called nitrogen fixation.
What are the key player in nitrogen fixation
Legumes and symbiotic bacteria associated with their root nodules called nitrogen fixing bacteria.
What do nitrogen fixing bacteria do?
convert nitrogen in the soil to ammonia NH3 which can be taken up by some plants.
What happens after nitrogen has been fixed?
Other bacteria convert it into nitrate, in a process called nitrification.
What is the first step in nitrification?
Nitrosomonas convert ammonia to nitrite NO2
What is the second step in nitrification
Nitrite is converted into Nitrate by nitrobacter.
After nitrification happens what happens.
The nitrate is consumed by plants but not all plants consume nitrate.
What is the final step in the Nitrogen cycle?
Denitfrifcation
What is Denitrification
a process performed by a variety of bacteria fungi and other organisms. Nitrates in the soil are broken down by these organisms and nitrogen is released into the atmosphere.
