BIOL 438 Nitrification Test Questions
and Correct Answers
What is nitrification? What are the two steps of the process? ✅Oxidation of ammonia
(NH4+) to nitrite (NO2-) and Nitrate (NO3-)
1. ammonia oxidation to nitrite by ammonia-oxidizing bacteria (AOB)
NH3 + O2 + ADP + Pi --> NO2- + H+ + ATP
2. nitrite oxidation to nitrate by nitrite-oxidizing-bacteria
NO2- + O2 + ADP + Pi --> NO3- + ATP
What is the produced ATP used for in the nitrite-oxidizing bacteria (NOBs) ? ✅The
ATP is used to fix CO2 in the calvin cycle. This allows for NOBs to grow on glucose
Ammonia monooxygenase (amo) is similar to ...? ✅amo oxidizes NH3 to NH2OH. It is
similar to MMO of methanotrophic bacteria. They share similar inhibitors (which can be
used for ecological studies.
How many genes code for ammonia monooxygenase? ✅amoA and amoB
How does NH3 ---> NO2- in Nitrosomonas? ✅NH3 enters the periplasm (between the
outer and inner membrane), nad to oxidized by Amo (which is embedded in the inner
membrane) to NH2OH.
NH2OH goes to Hao which shuttles é to cytc, and the NO2- exits the organism via
diffusing out the outer membrane.
Where is the [H+] higher? In the periplasm, or the cytoplasm? ✅In the periplasm.
Phylums of AOB ✅Proteobacteria - β (most diversity)
Proteobacteria - γ (Nitrosococcus oceanus - marine, equatorial)
Some Archaea - thaumarchaeota
The dominant nitrifying bacteria in soil ✅Nitrosospira
Inhibitors of ammonia-oxidation ✅Acetylene (C2H2): suicide substrate for amo. This
was used to identify the 14C2H2 peptides involved in AMO
and Correct Answers
What is nitrification? What are the two steps of the process? ✅Oxidation of ammonia
(NH4+) to nitrite (NO2-) and Nitrate (NO3-)
1. ammonia oxidation to nitrite by ammonia-oxidizing bacteria (AOB)
NH3 + O2 + ADP + Pi --> NO2- + H+ + ATP
2. nitrite oxidation to nitrate by nitrite-oxidizing-bacteria
NO2- + O2 + ADP + Pi --> NO3- + ATP
What is the produced ATP used for in the nitrite-oxidizing bacteria (NOBs) ? ✅The
ATP is used to fix CO2 in the calvin cycle. This allows for NOBs to grow on glucose
Ammonia monooxygenase (amo) is similar to ...? ✅amo oxidizes NH3 to NH2OH. It is
similar to MMO of methanotrophic bacteria. They share similar inhibitors (which can be
used for ecological studies.
How many genes code for ammonia monooxygenase? ✅amoA and amoB
How does NH3 ---> NO2- in Nitrosomonas? ✅NH3 enters the periplasm (between the
outer and inner membrane), nad to oxidized by Amo (which is embedded in the inner
membrane) to NH2OH.
NH2OH goes to Hao which shuttles é to cytc, and the NO2- exits the organism via
diffusing out the outer membrane.
Where is the [H+] higher? In the periplasm, or the cytoplasm? ✅In the periplasm.
Phylums of AOB ✅Proteobacteria - β (most diversity)
Proteobacteria - γ (Nitrosococcus oceanus - marine, equatorial)
Some Archaea - thaumarchaeota
The dominant nitrifying bacteria in soil ✅Nitrosospira
Inhibitors of ammonia-oxidation ✅Acetylene (C2H2): suicide substrate for amo. This
was used to identify the 14C2H2 peptides involved in AMO
