APES Unit 1- 1.5 Nitrogen Cycle

What is the first step of the Nitrogen Cycle?

nitrogen fixation

Nitrogen Fixation

Process of converting nitrogen gas into ammonia

What are the 2 types of Nitrogen Fixation?

bacterial fixation and synthetic fixation

Bacterial Fixation

certain bacteria that live in the soil, convert N2 into ammonia (NH3)

- ex: rhizobacteria live in root nodules of legumes and fix N for them in return for animo acids from the plant

Synthetic Fixation

humans combust FFs to convert N2 gas into nitrate (NO3-)

- ex: NH3 is added to synthetic fertilizer and applied to agricultural soils

What is the second step of the Nitrogen Cycle?

assimilation

Assimilation

plants and animals taking Nitrogen in and incorporating it into their body

- ex: plant roots take in NO3 or NH3 from soil; animals assimilate N by eating it or other animals

What is the third step of the Nitrogen Cycle?

ammonification

Ammonification

soil bacteria, microbes/decomposers conerting waste and dead biomass back into NH3 and returning it to soil

What is the fourth step of the Nitrogen Cycle?

nitrification

Nitrification

ammonia is converted to nitrate ions (NO3-)

What is the last step in the Nitrogen Cycle?

denitrification

Denitrification

Conversion of nitrates into nitrogen gas that will be released into the atmosphere