The Nitrogen Cycle

Nitrogen cycle

What it nitrogen necessary for making?

Amino acids (proteins and nucleic acids)

What percent of the atmosphere is is nitrogen?

80%

What forms of nitrogen can plants use? What are their formulas?

Ammonium (NH₄ +) and nitrate (NO_3^-)

What is nitrogen fixation in the soil?

The process where N₂ is converted into ammonia and nitrates by bacteria in the soil

What is nitrogen fixation by lightning?

Lightning converts N₂ into ammonium and nitrates, which is then carried by rain to the soil

What is nitrogen fixation by companies?

Companies turn N₂ into ammonium and nitrates

What is nitrification?

Ammonia is converted in to nitrite, then nitrate, making it usable to plants (by bacteria)

What is assimilation?

Plants take in nitrogen compounds from the soil with their roots (ammonia, nitrite and nitrate ions, or ammonium ions) and are used in formation of plant and animal proteins

Ammonification

When organisms die or excrete waste, nitrogen compounds are broken down by decomposers (bacteria and fungi) in the soil into ammonia

Denitrification

Nitrate converts back into N₂ by bacteria. The bacteria takes the oxygen and the N₂ is released back into the atmosphere

What is an aerobic organism?

An organism that needs oxygen to produce ATP

What is an anaerobic organism?

An organism that doesn’t need oxygen to produce ATP

What is the chemical formula for ammonium?

NH_{4 ⁺}

What is the chemical formula for ammonia?

NH₃

What is the chemical formula for nitrate?

NO₃ ^-

What is the chemical formula for nitrite?

NO_{2 ^-}