APES 1.5 Nitrogen Cycle

Nitrogen Cycle

A series of processes that convert nitrogen in the atmosphere into forms usable by living organisms and back again.

Most Abundant Gas

Nitrogen is the most prevalent gas in the Earth's atmosphere.

Inert Gas

Nitrogen is relatively unreactive and does not easily form compounds.

Ecosystem Role

The nitrogen cycle is crucial for the functioning and health of ecosystems.

Limiting Factor

Nitrogen often limits the growth of producers because it is required in large amounts for certain biological processes.

Amino Acids

Nitrogen is essential for the formation of amino acids, which are the building blocks of proteins.

Nucleic Acids

Nitrogen is also vital for the synthesis of nucleic acids, such as DNA and RNA.

Nitrogen Fixation

The process of converting atmospheric nitrogen (N2) into ammonia (NH3) or other usable forms.

Biotic Nitrogen Fixation

Biological processes that convert N2 into ammonia, typically carried out by certain bacteria.

Abiotic Nitrogen Fixation

Non-biological processes that convert N2 into nitrate (NO3).

Assimilation

The uptake of nitrogen by producers in the form of ammonium (NH4+) or nitrate (NO3-).

Consumer Assimilation

Consumers obtain nitrogen by eating producers that have assimilated it.

Ammonification

The process by which decomposers convert biological nitrogen compounds into ammonium (NH4+).

Nitrification

The conversion of ammonium (NH4+) into nitrite (NO2-) and then into nitrate (NO3-) by nitrifying bacteria.

Denitrification

The process by which denitrifying bacteria convert nitrate (NO3-) into nitrous oxide (N2O) and eventually nitrogen gas (N2) in low-oxygen environments.