Transcript Principles of Ecology - Mill Creek High School

Cycles
• All organisms need water, minerals, and other lifesustaining materials to survive.
Ex. Hydrologic – necessary for all life
Ex. Carbon – backbone of organic
compounds (carbs, lipids, proteins)
Ex. Phosphorus – uprights of DNA ladder
Ex. Nitrogen – needed to make amino acids
• Elements, chemical compounds, other forms of matter
are passed from one org to another and from one part of
the biosphere to another through BIOGEOCHEMICAL
CYCLES.
The hydrologic cycle
Perry
Condensation, Precipitation, Infiltration, Runoff, Evaporation
Carbon Cycle—
Perry
Carbon is the KEY ingredient in ALL living things
Volcano
Fossil
Fuels
Decomposition
Nitrogen Cycle—
Perry
Nitrogen is abundant in the atmosphere, but must be ‘fixed’ to get in to living systems
– ONLY a certain type of bacteria can do this!!!
5 terms to be sure of…
• Nitrogen fixation: The incorporation of atmospheric nitrogen
by either free-living bacteria in the soil or by bacteria living
mutualistically with plant roots.
• Ammonification:
the conversion of organic nitrogen to
ammonium (NH4+) by the action of decomposers (ex. fungi, bacteria).
• Nitrification: The chemical process in which a nitrogen group is
added to an organic compound. This converts dead organic material into
nitrates and nitrites by soil bacteria. Autotrophs use nitrates and nitrites
for nutrient needs.
• Assimilation:
the addition of material to autotrophs for use in
matter recycling and flow of energy
• Denitrification:
the return of nitrogen to the atmosphere by
bacteria (convert to gaseous form)
Phosphorus Cycle –
Perry
no atmospheric component at all!