Download CYCLING IN THE ECOSYSTEM

CYCLING
IN THE
ECOSYSTE
M
18.4
pp. 371-374
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
WATER CYCLE
WATER CYCLE
•
Evaporation: water vapor enters the atmosphere
WATER CYCLE
•
•
Evaporation: water vapor enters the atmosphere
Transpiration: evaporation of water through the
leaves of plants
WATER CYCLE
•
Precipitation: water vapor that leaves the
atmosphere
CARBON CYCLE
CARBON CYCLE
 Photosynthesis:
converting light energy into organic
compounds (C6H12O6)
 CO2 + H2O  C6H12O6
CARBON CYCLE
Cellular
respiration: breaks down sugar to
release energy and CO2 is released into atmosphere
(C6H12O6  CO2 + H2O + ATP)
CARBON CYCLE
Combustion:
releases CO2
burning of fossil fuels for energy
NITROGEN CYCLE
• 70% of atmosphere is nitrogen, but it is not in a ready to
use form
• N2 needs to converted into NH3 (ammonia)
NITROGEN CYCLE
nitrogen fixation: bacteria convert nitrogen gas
(N2) to usable form, NH3 (ammonia)
NITROGEN CYCLE
nitrogen fixation: bacteria convert nitrogen gas
(N2) to usable form, NH3 (ammonia)
ammonification: decomposers break down wastes
(urine, feces, death) to NH3
NITROGEN CYCLE
nitrification: bacteria convert NH3
to nitrates
(NO3-) i.e. like fertilizers
assimilation: plants absorb nitrate to make
amino acids (enters food chain)
NITROGEN CYCLE
Denitrification: bacteria
atmosphere (NO3-  N2)
return nitrogen to
Complete Cycles trifold
 Use
textbook and handout
to draw cycles in the
appropriate area.
 Cycles
should be neat,
simple, labeled, and
colored