Nitrogen CycleNitrogen CycleA. Nitrogen FactsA. Nitrogen Facts

Makes up Makes up DNA & proteins DNA & proteins (muscle function).(muscle function). Help plants grow. Help plants grow.

Where Nitrogen is Found (store):Where Nitrogen is Found (store): Atmosphere (78% is Atmosphere (78% is NN22)) OceansOceans Organic matter in soilOrganic matter in soil Lakes, marshes, organismsLakes, marshes, organisms

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4

3

2

4

1

B. How Nitrogen Changes Form:B. How Nitrogen Changes Form: -- NN22 is is not usable not usable by plants or animals, so it has to be converted by plants or animals, so it has to be converted

to other forms.to other forms.- Plants can use Plants can use NONO33

-- (nitrate) (nitrate) andand NHNH44++ (ammonium (ammonium))

Part I. Making nitrogen into Part I. Making nitrogen into usable usable form (3 steps)form (3 steps)1.1. Nitrogen Fixation Nitrogen Fixation process in which process in which nitrogen gas nitrogen gas (N(N22)) is converted into a is converted into a

compound that contains compound that contains ammonium (NHammonium (NH44++) ) or or nitrates (NOnitrates (NO33

--)) Occurs in 3 ways: Occurs in 3 ways: AtmosphereAtmosphere: : Soil: Soil: NN22 NH NH4 4

+ + (Nitrogen fixing bacteria eg. Rhizobium) (Nitrogen fixing bacteria eg. Rhizobium) Water: Water: NN22 NH NH4 4

+ + (Cyanobacteria)(Cyanobacteria) N2 NO3 -(lightening)

Not in the Data Booklet

2.2. Nitrification Nitrification done by done by nitrifying bacterianitrifying bacteria.. 2 Stages: 2 Stages:

3. Uptake3. Uptake The process of taking up usable nitrogen The process of taking up usable nitrogen

by plants and incorporated into plant DNAby plants and incorporated into plant DNA NONO33

-- is sucked into plants & used for is sucked into plants & used for growth.growth.

Herbivores eat plants & use Herbivores eat plants & use NN for making for making proteinsproteins & & DNA.DNA.

Step 1NO3

- (nitrate)NH4+

(ammonium)NO2

- (nitrite) Step 2

Part II. Return NPart II. Return N22 to ecosystem to ecosystem

1.Denitrification 1.Denitrification done by denitrifying bacteria & volcanic eruptionsNONO33

- - NN22

2.2. Decomposition: Decomposition: nitrogen from DNA/protein of dead organism NH4

+ (Bacteria and Fungi)

3. Volcanic Ash: Return ammonia (NH3) to atmosphere

C.C. Human activities affect the nitrogen cycle.Human activities affect the nitrogen cycle.1.1. Burning fossil fuels + Land clearingBurning fossil fuels + Land clearing

► NONO & & NONO22 producedproduced lead to lead to Acid RainAcid Rain

Question: Leaching of nitrogen into water ways, what Question: Leaching of nitrogen into water ways, what problem could this make?problem could this make?

Algal BloomAlgal Bloom2. Overfertilization 2. Overfertilization NHNH44

++ & & NONO33-- leach into soil leach into soil

& waterways.& waterways.► huge growth in huge growth in

aquatic algae = aquatic algae = eutrophicationeutrophication

Algal blooms Algal blooms use up all use up all COCO22 & O& O22, , blocking sunlightblocking sunlight and and therefore kill many aquatic therefore kill many aquatic organisms.organisms.Algal blooms can produce Algal blooms can produce neurotoxin that poison the neurotoxin that poison the animalsanimals

The Phosphorous CycleThe Phosphorous CyclePhosphorous FactsPhosphorous Facts

In Plant, Phosphorous contributes to In Plant, Phosphorous contributes to root growthroot growth, , stem stem strengthstrength and and seed productionseed production..

In animals/human, phosphorous is important for In animals/human, phosphorous is important for bonebone development and DNAdevelopment and DNA..

Where Phosphorous is Found (storage):Where Phosphorous is Found (storage): Found in Found in phosphate rocks (POphosphate rocks (PO44

3–3–, HPO, HPO442–2–, H, H22POPO44

--)) and and sediments on the ocean floor; sediments on the ocean floor; Not in the AtmosphereNot in the Atmosphere

The Phosphorous CycleThe Phosphorous Cycle

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2

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3*

456 6

789

10

1111

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13

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B.B. How Phosphorous Changes FormHow Phosphorous Changes Form..

1.1. WeatheringWeathering (breaking down rock into smaller pieces).(breaking down rock into smaller pieces).a) a) Chemical weathering Chemical weathering (Chemical reaction) :(Chemical reaction) : acid rain or lichens releases acid rain or lichens releases phosphates (POphosphates (PO44

3-3- ) )b) b) Physical weathering Physical weathering (physical process) :(physical process) : wind, water and freezing release the wind, water and freezing release the phosphates.phosphates.

2.2. UptakeUptake: : plants suck up plants suck up POPO443-3-, then are eaten by , then are eaten by

animals.animals.3.3. Decomposition: Decomposition: Bacteria break down organic matter Bacteria break down organic matter

& & phosphorous is returned to soil.phosphorous is returned to soil.4.4. Geologic UpliftGeologic Uplift:: when rocks under the ground are when rocks under the ground are

pushed up pushed up mountains mountains weathering (mountain weathering (mountain building).building).

C. Human activities affect the Phosphorous C. Human activities affect the Phosphorous Cycle.Cycle.1. 1. Fertilizer, P-containing detergents, animal Fertilizer, P-containing detergents, animal waste (bird’s dropping or guano),industrial waste (bird’s dropping or guano),industrial waste, untreated human waste waste, untreated human waste add additional add additional phosphate to the phosphorous cycle. phosphate to the phosphorous cycle. 2. Guano: dried excrement of fish-eating sea dried excrement of fish-eating sea birds, deposited in rocky coastal regionsbirds, deposited in rocky coastal regions

Q. How much phosphorus does guano contribute Q. How much phosphorus does guano contribute to the phosphorus cycle?to the phosphorus cycle?

2. Too much phosphorous can cause death in 2. Too much phosphorous can cause death in some animals some animals (Eutrophication)(Eutrophication)

How Changes in Nutrient Cycles How Changes in Nutrient Cycles Affect BiodiversityAffect Biodiversity

To Review:To Review:Any significant changes to any of these nutrients (C, H, O, N

or P) can greatly impact biodiversity.1.1. Carbon cycleCarbon cycle changes changes climate change & global climate change & global

warming.warming.2.2. Too much Too much nitrogennitrogen can allow certain plant species to out- can allow certain plant species to out-

compete other species.compete other species.3.3. Decreased levels of Decreased levels of phosphorousphosphorous

slow growth of algae slow growth of algae (important producers).(important producers).

►Homework: Pg 91 # AllHomework: Pg 91 # All►Handout from yesterday. Handout from yesterday. ►Chapter 2 Test on Friday. Chapter 2 Test on Friday.