1. Biochemical Cycles- closed circles or cycles of materials from nonliving to living organisms and back to nonliving. Examples : Water, carbon, nitrogen and phosphorus Biology, Geology and Chemistry Cycles Nutrients through the Ecosystem

2. I. General Information A. Biogeochemical cycles materials cycle between the living and physical (non-living) parts of an ecosystem B. Types of cycles 1. Water 2. Energy 3. Carbon 4. Nitrogen

3. II. Water Cycle

4. A. Driven by the Sun B. Steps of Water Cycle B. Steps of Water Cycle 1. Evaporation – a. Sun heats Earth a. Sun heats Earth b. H 2 O evaporates b. H 2 O evaporates c. H 2 O goes into atmosphere as H 2 O vapor H 2 O vapor

5. II. Water Cycle 2. Condensation H 2 O condenses H 2 O condenses (goes from gas to liquid) to form clouds

6. II. Water Cycle 3. Precipitation H 2 O leaves clouds, falls on Earth H 2 O leaves clouds, falls on Earth E.g. rain, snow, sleet, hail E.g. rain, snow, sleet, hail 4. Percolation / Infiltration H 2 O enters soil, becomes groundwater H 2 O enters soil, becomes groundwater

7. II. Water Cycle 5. Run–off Some H 2 O moves on surface to rivers, lakes & oceans 6. Transpiration H 2 O released from plant leaves, H 2 O released from plant leaves, returns to atmosphere returns to atmosphere

8. II. Water Cycle C. Where is the H 2 O on Earth? 1. Oceans 97.2% 2. Glaciers 2.15% 3. Lakes 0.009% 4. Soil 0.005% 5. Atmosphere 0.001% 6. Streams 0.0001%

9. II. Water Cycle

10. III. Carbon Cycle

11. A. How does carbon enter the living part of the cycle? 1. Photosynthesis Plants, algae, & cyanobacteria use CO 2 to make organic compounds (sugars) 2. Nutrients move C through trophic levels Consumers move organic compounds

12. III. Carbon Cycle B. How does carbon get back into the physical part of the cycle? 1. Cellular Respiration  O 2 used to break down sugars  CO 2 released into atmosphere

13. III. Carbon Cycle 2. Combustion  Fossil fuels & wood burned CO (carbon monoxide) released to atmosphere  Factory & Auto emissions release CO to atmosphere

14. III. Carbon Cycle 4. Decomposition of waste and dead materials  Some dead organisms become fossil fuels  Some dead organisms and waste decay, returning nutrients to the soil  Erosion – –CaCO 2 from shells returned to system as sediment –Shelled organisms die –Sediment returns C to ecosystem by erosion (wind & water)

15. III. Carbon Cycle

16. IV. Nitrogen Cycle

17. A. General information 1. N needed to make proteins Proteins = large molecules that perform almost all of living organisms’ vital f(x)s (functions)

18. IV. Nitrogen Cycle 2. N hard to convert into a form usable by plants 3. Most steps of N cycle occur in the soil 4. Bacteria very important to the N cycle

19. IV. Nitrogen Cycle B. Steps of the N cycle 1. Nitrogen fixation Bacteria work with Bacteria work with legumes legumes (peas, beans, peanuts) to take N 2 from atmosphere, put it into the soil

20. IV. Nitrogen Cycle 2. Ammonification  Animals & plants deposit nitrogenous waste  Decomposers  (bacteria & fungi) convert organic N (proteins) to ammonia (NH 3 )

21. IV. Nitrogen Cycle 3. Nitrification Another kind of bacteria convert nitrogen compounds NH 3 → NH 4 + → NO 2 - + NO 3 - 4. Denitrification 4. Denitrification Another kind of bacteria convert nitrites and nitrates to nitrogen gas NO 2 - + NO 3 - → N 2

22. IV. Nitrogen Cycle 5. Assimilation- the absorption and incorporation of Nitrogen into plant and animal compounds

23. IV. Nitrogen Cycle