Unit 10- Pyramids and nitrogen cycle

Question 1

In what form is energy lost each tropic level

Answer 1

• the chemical energy in uneaten parts
• movement energy of the consumers
• heat energy

Question 2

How is mass lost each tropic level

Answer 2

Through carbon dioxide in respiration
Uneaten parts
Waste, eg faeces

Question 3

There are 7 stages in the nitrogen cycle, list them:

Answer 3

1) Nitrogen gas to ammonia
2) ammonia to nitrite
3) nitrite to nitrates
4) nitrates to nitrogen gas
The the side cycles
5) ammonia to nitrates
6) nitrates to plan proteins
7) plant proteins to ammonia

Question 4

Explain the conversion of Nitrogen gas to Ammonia

Answer 4

• Nitrogen gets fixed by Rhizobium nitrogen fixing bacteria in the root nodules of leguminous plants, this is a mutualistic relationship providing NH3 for the plant and glucose for the bacteria
• this process can also be artificially done via Haber cycle

Question 5

Explain the process of ammonia to nitrites

Answer 5

Ammonia is oxidises by nitrifying nitrosomonas bacteria in an ex other mix reaction where the bacteria uses the heat to produce ATP

Question 6

Explain the stage nitrite to nitrate

Answer 6

Nitrites get further oxidised by the nitrifying bacteria nitrobacter to produce nitrates

Question 7

Describe the process of nitrates to nitrogen gas an another product

Answer 7

Denitrifying bacteria in anaerobic conditions convert nitrates into nitrogen gas and nitrogen oxide

Question 8

What is the process by which ammonia is converted into nitrates

Answer 8

Oxidation via lightening or nitrosomonas and nitrobacter

Question 9

How do nitrates get converted into ammonia via plant uptake?

Answer 9

• nitrates are assimilated by plants to produce plant proteins
• plants dies and saprobionts begin the process of decomposition
• saprobiotic nutrition: extracellular protease is released to hydrolyse the peptide bond into amino acids, then deaminase enzymes break the amino group off the molecule to produce ammonia and carbohydrates