Nutrient Cycles Flashcards
1
Q
Describe the role of saprobionts in the nitrogen cycle.
A
- decompose proteins
- releasing ammonia
2
Q
Nitrification is…
A
- NH3 (ammonia) > NO2 (nitrites) > NO3 (nitrates)
- using nitrifying bacteria
3
Q
Denitrification is…
A
- NO3 (nitrates) > N2 (nitrogen gas)
- NO3 (nitrates) > NO2 (nitrites)
- using denitrifying bacteria
4
Q
Nitrogen fixation is…
A
- N2 (nitrogen gas) > NH3 (ammonia)
- using nitrogen fixing bacteria
5
Q
Decomposition is…
A
- nitrogen containing compounds to Ammonia (ammonification)
- using saprobionts
6
Q
Nitrogen found in…
A
- amino acids
- proteins
- nuclei acids
- ADP
- ATP
- NADP
- NAD
- FAD
7
Q
Describe how the action of microorganisms in the soil produces a source of nitrates for crop plants.
A
- proteins into ammonia
- by saprobionts
- ammonia into nitrite
- nitrite into nitrates
- by nitrifying bacteria
- nitrogen gas to ammonia
- by nitrogen fixing bacteria in soil
8
Q
Explain how carbon containing compounds are absorbed and used for growth by saprobionts in soil.
A
- extracellular digestion
- by secretion of enzymes
- absorption of digested products
- synthesis of structural compounds
- respiration provide energy for growth
9
Q
Describe why phosphates are needed by a growing plant.
A
- production of phospholipids
- in cell membranes
- synthesis of ATP
- production of DNA
- production of RNA
- production of NADP
10
Q
Describe how a lack of phosphates in the soil surrounding a plant can affect its growth.
A
- less ATP so less respiration
- less nucleotides so less DNA
- less RuBP so less CO2 fixed into sugar
- make phospholipids for membranes
11
Q
Advantages of having Mycorrhizae growth near plants.
A
- help plants defend themselves
- help plants take up nitrates
12
Q
Describe process of eutrophication.
A
- nitrates into waterway
- increased algal bloom
- light blocked out
- aquatic plants cant photosynthesise and die
- increase in saprobionts
- increased aerobic respiration
- organisms die due to lack of oxygen
- increase in anaerobic respiration
- production of toxins
= putrid conditions
13
Q
Describe how you obtain a quantitative measurement of water cloudiness.
A
- use of colorimeter
- measure the absorbance of light
- standardisation e.g. same water volume, same light wavelength
14
Q
Environmental impact of using fertilisers.
A
- reduced species diversity / plants adapted to nitrates outcompete other
- environmental issues / less nitrate returned to soil as less decomposition
- leaching / nitrates washed into water
