1. Biogeochemical Cycles

2. Oxygen Cycle Autotrophs: Release O2 into atmosphere via photosynthesis
All life: Absorbs O2 to be used during cellular respiration
Respiration: creates ATP energy for cells

3. Carbon Cycle
CO2
CO2
Carbon = (organic molecules) carbohydrates, proteins, lipids, nucleic acids
Plants & autotrophs:
Intake: Absorb CO2 from atmosphere
Create glucose & sugar via photosynthesis
Output: Release CO2 during respiration

4. Carbon Cycle Consumers
Intake: Carbon moves up the food chain as 1 feeds on another
Output: Release CO2 during respiration

5. Carbon Cycle Decomposers Input: Feed on dead organic matter
Output: Release CO2 during respiration
Output: Organic molecules returned to soil during decomposition

6. Carbon Cycle Human Industry
CO2
Human Industry
Output: Release CO2 into atmosphere when fossil fuels (coal, oil, natural gas) are burned

7. Nitrogen Cycle N = 78% atmosphere (most unusable) Soil Bacteria
Ammonia
Nitrates
N = 78% atmosphere (most unusable)
Soil Bacteria
Nitrogen fixation: convert atmospheric nitrogen into ammonia
Nitrification: ammonia converted into nitrates

8. Nitrogen Cycle
Nitrates
Plants
Absorb nitrates through their roots

9. Nitrogen Cycle Animals
Nitrates
Animals
Ingest nitrates through the food chain (plants eaten)

10. Nitrogen Cycle Decomposers
Ammonia
Ammonia
Ammonia
Decomposers
Return ammonia to soil by feeding on dead matter

11. Nitrogen Cycle Lightning
Energy breaks atmospheric nitrogen into Nitrogen oxide
Nitrogen oxide falls in rain to soil

12. Phosphorus (P) Cycle No phosphorus in atmosphere Rocks P
Phosphorus released by weathering of rocks

13. Phosphorus (P) Cycle P
Plants
Absorb P into their roots

14. Phosphorus (P) Cycle Animals P Ingest P when plants eaten
P continues to move up food chain

15. Phosphorus (P) Cycle Decomposers P
Breakdown dead matter and release P into soil

16. Phosphorus (P) Cycle Human Contribution
Adding excess P from fertilizers…. P washes into lakes, etc…
Excess P causes extreme algae growth