1. Biogeochemical Cycles
In studying cycling of water, carbon, nitrogen, and phosphorus, ecologists focus on four factors:
1. Each chemical’s biological importance
2. Forms in which each chemical is available or used by organisms
3. Major reservoirs for each chemical
4. Key processes driving movement of each chemical through its cycle
Bozeman Lesson on Biogeochemical Cycles

2. Do NOW: With your table group, complete the task below
Do NOW: With your table group, complete the task below. Time limit – 10 minutes
Two people will obtain blue, red and white paper.
Use templates to make 8 large circles, 5 medium size circles, and 7 small circles.
Large circle color =blue Medium=red Small=white
Use a marker, write an N on all blue circles, a O on the red circles and an H on the white circles.
The other two people will obtain a yellow piece of paper and marker.
Create yellow paper flashcards with the following terms on one side: nitrogen fixation, nitrification, denitrification, ammonification, assimilation
When circles and flashcards are complete, think about which two processes go along with each nitrogen form: Nitrite, Nitrate, Ammonia, Protein, Nitrogen, Ammonium, Write your answer on a piece of scratch paper.
Have students make the yellow processes and the red/blue/white circles
Ask, What component of a biogeochemical cycle is represented by the yellow strips of paper? Processes
Now look at your scrap paper – which two process involve nitrogen? Nitrate? Ammonia or Ammonia?
Notes on the processes – Have students write the chemical change on the front with process, i.e. nitrogen fixation N2  NH3/NH4+
Show students that N is cycling by circling the N
Tell student to make each form. When done…create the nitrogen cycle on the lab table. Draw it or take a picture of it and upload it to drive.

3. Reservoirs: Forms: How many times are
nitrogen
nitrate
nitrite
ammonia/ammonium
proteins contain “N”
urine contains ammonia
Reservoirs:
Atmosphere
Soil
Organisms
plants
animals
bacteria
fungi
Consumption
Denitrification
Assimilation
Excretion
Nitrogen fixation
Ammonification
Nitrification
Animals and Humans – consumption of plants (hebivores) or consumption of animal (carnivore) or consumption of both (omnivore) moves the nitrogen in cycle. Plants and animals contain proteins
Plants – assimilation – absorb the nitrates or nitrites from the soil
Bacteria – most important organism for moving the nitrogen in the cycle.
Nitrogen fixation uses the Bacteria Rhizobium
How many times are
bacteria helping to cycle nitrogen?

4. Nitrogen Cycle Important because…
Used to make proteins which are organic compounds that contain nitrogen
Used to make nucleic acids which are organic compounds (DNA and RNA) which contain nitrogen

5. Types of Proteins (Chapter 3, Section 11)
Transport – used to carry specific substance, example is hemoglobin protein for carrying oxygen in blood
Chemical reaction – used to help make a reaction go, example is an enzyme
Signal – used to make a cell do a specific task, for example a neurotransmitter tells a nerve cell to send a message to the brain or body part
Storage – used as a source of nutrients for use, for example ovalbumin (egg white in eggs)
Contraction – used to make something move, for example muscle proteins contract the bicep muscle
Receptor – used to receive a message from another cell to trigger a specific action, for example, insulin binds to insulin receptor and cell takes in extra sugar from blood
Types of Proteins (Chapter 3, Section 11)

6. Nitrogen Cycle
Animation of the Nitrogen Cycle
Nitrogen Cycle Song

7. Simplified Diagram of Nitrogen Cycle
Nitrogen fixation – N2 to NH3
Nitrification – NH3 to NO2 or NH3 to NO3
Assimilation – NO3 to Proteins in Plants
Ammonification – Dead plants or animal to
NH3 or Animal wastes to NH3
Denitrification – NO3 or NO2 to N2
Simplified Diagram of Nitrogen Cycle

8. Phosphorus Cycle