Name:____________________________________________________________

Two-Column Notes

Nitrogen Cycle

Main Idea DetailsNitrogen moves

continuously throughout the Nitrogen Cycle

Nitrogen gas is the most abundant element in the atmosphere

Most nitrogen must be converted or FIXED into useful nitrogen compounds before being used

After it is fixed, it can move through the ecosystem in the Nitrogen Cycle (POOP AND BACTERIA CYCLE!)

1. Nitrogen gas exists in the atmosphere

o 78% of atmosphere is composed of nitrogen gas

o Most of the nitrogen cannot be used in this form by living things: plants, animals, fungi, protista

2. Ammonification

is when nitrogen in

waste and dead matter enter the

soil through decomposition

Bacteria in the soil convert nitrogen into a molecule called ammonia (NH3)

Ammonia is still pretty toxic and this nitrogen compound can still NOT be used

3. Nitrogen in the soil can be fixed through

three main ways

Atmospheric Fixation – Lightning Industrial Fixation – Put in Fertilizer Biological Fixation – Bacteria live on roots of

plants and make compounds for plants to use

4. Nitrogen Other bacteria take the ammonia and convert it

Name:____________________________________________________________

Fixation is when soil

bacteria change the nitrogen

into a form that can be used by

plants

to another compound that is save for organisms to use (NO3)

This is an example of MUTUALISM o The bacteria get a comfy place to live on

the roots of plants and the plants are able to get nitrogen in order to make proteins

5. Assimilation is when plants

take in the fixed nitrogen in

order to make proteins

Plants take in the compounds that they can use in order to make important molecules

6. Consumers eat the

producers and the nitrogen now becomes part of them

Nitrogen compounds are transferred from plants to animals, then continue in the cycle after death or through waste

7. Denitrification is when another

soil bacteria changes ammonia

back into nitrogen gas

Bacteria convert the nitrogen compound back into nitrogen gas, N2, releasing it back into the atmosphere