1. CYCLING IN THE ECOSYSTEM
18.4 pp

2. DEFINITIONS
Ecosystem: an environment where the living (biotic) and non-living (abiotic) things affect one another
Biogeochemical process: circulation of substances through living organisms and the environment

3. WATER CYCLE

4. WATER CYCLE
Evaporation: water vapor enters the atmosphere

5. WATER CYCLE Evaporation: water vapor enters the atmosphere
Transpiration: evaporation of water through the leaves of plants

6. WATER CYCLE
Precipitation: water vapor that leaves the atmosphere

7. CARBON CYCLE

8. CARBON CYCLE
Photosynthesis: converting light energy into organic compounds (C6H12O6)
CO2 + H2O  C6H12O6

9. CARBON CYCLE
Cellular respiration: breaks down sugar to release energy and CO2 is released into atmosphere
(C6H12O6  CO2 + H2O + ATP)

10. CARBON CYCLE
Combustion: burning of fossil fuels for energy releases CO2

11. NITROGEN CYCLE
70% of atmosphere is nitrogen, but it is not in a ready to use form
N2 needs to converted into NH3 (ammonia)

12. NITROGEN CYCLE
nitrogen fixation: bacteria convert nitrogen gas (N2) to usable form, NH3 (ammonia)

13. NITROGEN CYCLE
nitrogen fixation: bacteria convert nitrogen gas (N2) to usable form, NH3 (ammonia)
ammonification: decomposers break down wastes (urine, feces, death) to NH3

14. NITROGEN CYCLE
nitrification: bacteria convert NH3 to nitrates (NO3-) i.e. like fertilizers
assimilation: plants absorb nitrate to make amino acids (enters food chain)

15. NITROGEN CYCLE
Denitrification: bacteria return nitrogen to atmosphere (NO3-  N2)

16. Complete Cycles trifold
Use textbook and handout to draw cycles in the appropriate area.
Cycles should be neat, simple, labeled, and colored