8.2: The Nitrogen Cycle

Question 1

Why is the nitrogen cycle important?

Answer 1

• nitrogen is important for the formation of amino acids, proteins and nucleic acids

Question 2

Where is the main reservoir of nitrogen?

Answer 2

• The atmosphere (N2)

Question 3

What happens in the atmosphere during the nitrogen cycle?

Answer 3

1. nitrogen must be converted to NH4+ or NO3- for uptake by plants via nitrogen fixation by bacteria
2. Organic nitrogen is decomposed to NH4+ by ammonification
3. NH4+ is decomposed to NO3- by nitrification

Question 4

What occurs in denitrification?

Answer 4

Converts NO3- to N2