Nitrogen Cycle

Question 1

Why must Nitrogen be recycled

Answer 1

• Finite supply of nitrogen on earth so must be replaced from dead organisms , dead plants and animal waste products
• most recycling takes place in soil by bacteria

Question 2

Name 2 molecules with Nitrogen

Answer 2

• DNA
• amino acid

Question 3

What is Nitrogen Fixation

Answer 3

• Microorganisms convert N2 gas ~ NH3 ammonia
  And then to ~ NH4+

Question 4

What is Ammonification ?

Answer 4

• Bacteria and fungi break down Nitrogen containing molecules ~ releasing NH3 ammonia as waste product
• NH3 ~ NH4+ in soil ( free living bacteria)

Question 5

What is Nitrification ( 2 steps )

Answer 5

1- oxidation of NH4+ ~~ NO2- (Nitrite)

2- Oxidation of NO2- ~~ NO3- ( Nitrate)

Overall NH4+ goes to NO3- ( ammonium ~ Nitrates)
Done by nitrifying bacteria

Question 6

What is Denitrification

Answer 6

Happens when Nitrifying + Nitrogen fixing bacteria cannot function due to low oxygen

• increase in anaerobic denitrifying bacteria
• converts nitrates NO3- ~ N2 gas

Wasteful process reducing availability of Nitrogen contains compounds for plants