SOIL SCIENCE 326 EXAM 2 QUESTIONS AND 100%
VERIFIED ANSWERS
- atmosphere
- soils
- plants
Where does nitrogen form?
- N2 (78%)
- N2O (very small value)
- nitric oxide and nitrogen dioxide pollutants
What forms of nitrogen exist in the atmosphere?
- NO3- (nitrate)
- NO2- (nitrite)
- NH3 (ammonia)
- amino acids
- urea
What forms of nitrogen exist in the soil?
1-6%
What percentage of plant tissue is nitrogen?
- proteins
- base pairs
- prosthetic groups of proteins
- hormones
- osmoregulation
- biochemicals
Where is nitrogen found in plant cells?
, - proteins
- chlorophyll
- DNA
What are the 3 primary uses of nitrogen in plant cells?
Plants do not use nitrogen in the form of nitrate and ammonium; it is reduced
into usable forms
What happens immediately after soil nitrogen is uptaken by plants?
Takes place in the root and shoot, using nitrate reductase enzymes
Where and how is nitrate reduced?
Nitrite reductase produces ammonium from nitrite
What enzyme produces ammonium from nitrite?
Ammonium that has either been converted to taken up directly undergoes
ammonium assimilation to amino acids (glutamine synthase or glutamate
synthase enzymes)
What happens to ammonium uptaken by plants?
In soil, N-redox reactions are driven by soil moisture status & microbes needing
electrons
How is nitrogen redox driven in soil?
N can gain or lose 8 electrons in these transformations
What is the magnitude of redox in nitrogen?
In plants, this is enzyme driven for plant metabolism
How is nitrogen redox driven in plants?
forms of N that are active in environment, or can be taken up by plants
(everything except N 2 - 78% of our atmosphere)
Reactive nitrogen
1. fossil fuel combustion
2. fertilizers
3. planting N2 fixing crops
VERIFIED ANSWERS
- atmosphere
- soils
- plants
Where does nitrogen form?
- N2 (78%)
- N2O (very small value)
- nitric oxide and nitrogen dioxide pollutants
What forms of nitrogen exist in the atmosphere?
- NO3- (nitrate)
- NO2- (nitrite)
- NH3 (ammonia)
- amino acids
- urea
What forms of nitrogen exist in the soil?
1-6%
What percentage of plant tissue is nitrogen?
- proteins
- base pairs
- prosthetic groups of proteins
- hormones
- osmoregulation
- biochemicals
Where is nitrogen found in plant cells?
, - proteins
- chlorophyll
- DNA
What are the 3 primary uses of nitrogen in plant cells?
Plants do not use nitrogen in the form of nitrate and ammonium; it is reduced
into usable forms
What happens immediately after soil nitrogen is uptaken by plants?
Takes place in the root and shoot, using nitrate reductase enzymes
Where and how is nitrate reduced?
Nitrite reductase produces ammonium from nitrite
What enzyme produces ammonium from nitrite?
Ammonium that has either been converted to taken up directly undergoes
ammonium assimilation to amino acids (glutamine synthase or glutamate
synthase enzymes)
What happens to ammonium uptaken by plants?
In soil, N-redox reactions are driven by soil moisture status & microbes needing
electrons
How is nitrogen redox driven in soil?
N can gain or lose 8 electrons in these transformations
What is the magnitude of redox in nitrogen?
In plants, this is enzyme driven for plant metabolism
How is nitrogen redox driven in plants?
forms of N that are active in environment, or can be taken up by plants
(everything except N 2 - 78% of our atmosphere)
Reactive nitrogen
1. fossil fuel combustion
2. fertilizers
3. planting N2 fixing crops
