Carbon Cycle Vocabulary
Biogeochemical cycle: cycling of material through biotic
& abiotic factors
Photosynthesis: process by which photoautotrophs trap
solar energy and use it to make sugar and O2
Respiration: process where food molecules are broken
down to produce energy and CO2
Reservoir: temporary holding place for carbon
Biosphere: any area that supports life
Atmosphere: CO2 reservoir
Biomass: total mass of all biotic factors
Fossil fuels: coal, oil (petroleum), gas
Ocean carbon: largest reservoir of carbon (dissolved CO2,
carbonate, bicarbonate)
Organic molecule: molecule that contain carbon
Combustion: process of burning
THE CYCLE for the “molecule of life”
 Carbon exists in abiotic environment as
o CO2 in atmosphere and dissolved in water
o carbonate rocks (limestone/coral)
o fossil fuels
o decomposing organic matter
 Carbon enters BIOTIC environment through
o PHOTOAUTOTROPHS
 Carbon returns to ABIOTIC environment through
o RESPIRATION
o FOSSIL FUEL BURNING
o DECAY
Nitrogen Cycle Vocabulary
Nitrogen Fixation: nitrogen is inert (not reactive) so it
must have help to convert atmospheric nitrogen (N2) into
usable nitrogen
 Atmospheric: Lightning splits N2 molecules and they
combine with O2 molecules
 Industrial: High P and T combines N2 & H2 to form
ammonia (fertilizers)
 Biological: Symbiotic relationships with plant roots
OR nitrogen fixing bacteria in soil
Decay: organisms break down compounds and turn into
ammonia
Nitrification: converting organic nitrogen into nitrites
(NO2) or nitrates (NO3)
Denitrification: break down of nitrates to atmospheric
nitrogen (N2)
*** Both nitrification and denitrification need bacteria***
Why is nitrogen important???
 Nitrogen is a key component of proteins/nucleic acids
 Air is 79% nitrogen (largest reservoir of nitrogen)
Water Cycle Vocabulary a.k.a. Hydrologic Cycle
Evaporation: liquid water becoming vapor
 Transpiration: evaporation from a plant
Condensation : water vapor becoming a liquid
Runoff: water that runs through the soil into bodies of
water
Precipitation: rain, snow, sleet or hail
Groundwater: water under the ground, as in a well
THE WATER CYCLE
 Water undergoes condensation in a cloud.
 Precipitation falls to the ground.
 Water either:
o Becomes groundwater and evaporates
o Evaporation occurs off a body of water
o Transpiration occurs from plants
o The water goes into the soil, becomes runoff and
evaporates from the body of water.