2. The Phosphorus Cycle
Which Earth Systems Does Phosphorus Cycle Through??
How is This Different From the Cycling of Carbon??

3. Phosphorus is located in…
Sediments
Rocks
Water
Soil
Living
Organisms

4. Phosphorus is essential to living organisms. WHY???
Cell Membranes
Energy-storing Molecules
Lipids (Fats and Oils)
ATP and ADP
Phosphorus is essential to living organisms. WHY???
DNA & RNA
Combines w Calcium to form BONES and TEETH
Helps Metabolize Carbs, Fats, and Proteins

5. Most phosphate is LOCKED in SEDIMENTS & ROCKS. It is a very slow cycle.

6. Most Phosphorus is UNAVAILABLE to Plants…
BACTERIA convert INORGANIC (useable) phosphate into ORGANIC forms that plants can’t use.
ADSORPTION- INORGANIC phosphorus can be chemically bound to soil particles, making it unavailable to plants.
pH: INORGANIC phosphorus compounds need to be SOLUBLE to be taken up by plants.
If soil is too acidic or too basic, Phosphorus will bond with other compounds, making it less available to plants.
pH <4 or >8

7. Key Steps of the Phosphorus Cycle…
WEATHERING & EROSION cause rocks to release (INORGANIC) phosphate ions, which is distributed in soils and water.
and water

8. Key Steps to the Phosphorus Cycle…
PLANTS take up INORGANIC phosphate from the soil and water.
Animals eat plants
Phosphate is used in ORGANIC molecules, like DNA, ATP
Organism DIES (or produces WASTE) and ORGANIC phosphate returns to the soil.
and dead organisms

9. Key Steps to the Phosphorus Cycle…
In the SOIL, BACTERIA breakdown matter to INORGANIC phosphorus, which PLANTS can use. This is called MINERALIZATION

10. Key Steps to the Phosphorus Cycle…
Phosphorus in the SOIL runs off into WATER and eventually OCEANS.
It becomes part of SEDIMENTS over time.

11. How Do We Impact the Phosphorus Cycle?
1. Mining (for fertilizer and detergents)
Depletes resources (takes millions of years to replenish)
2. Deforestation
slash and burn clearing land for agriculture decreases available amounts. (held in trees and vegetation, not soil)
3. Waste
Agricultural and human waste contains high amounts of phosphorus, even when treated.

16. 5 2 8 7 1 3 1 6 2 4 ANIMAL DIES RETURNING ORGANIC PHOSPHORUS TO SOIL
EROSION 8
EUTROPHICATION 7 1
LEACHING
PLANTS TAKE UP INORGANIC PHOSPHATE FROM SOIL 3 1
WEATHERING
ANIMAL WASTE RETURNS ORGANIC PHOSPHORUS TO SOIL 6 2
ANIMALS EAT
PHOSPHATE USED TO BUILD ORGANIC MOLECULES (DNA & PROTEINS 4

17. Rally Coach 1 sheet per partner group 1 pencil per partner group
The 1st person starts with the paper, the other person starts with the pencil
1st person answers the question,
if they’re right, 2nd person hands them the pencil to write down the answer.
If they’re wrong, 2nd person coaches them to the right answer
Hand paper to 2nd person and repeat