1. Unit 8 Notes: Feeding Relationships

2. (1) What is a Feeding Relationship?
The transfer of energy and matter between different organisms in an ecosystem.

3. (2) Matter & Energy As One Organism Consumes Another:
The matter they are composed of changes form and is transferred to new cells.
The energy within the bonds of molecules is transferred to new cells.
Types of Energy within Organisms:
Chemical Potential Energy = The energy stored within the bonds of biomolecules.
Kinetic Energy = The energy being used by living cells right now.

4. (3) Autotrophs  Heterotrophs
Autotrophs take unusable energy (from sunlight / chemicals) and convert it into stored energy in sugars.
Heterotrophs eat autotrophs + each other to get stored energy from sugars.
As energy is transferred from organism to another…
Less energy is available for the next organism.
Some energy is lost to the environment.

6. (4) Food Chains
Shows the transfer of energy and matter throughout a single sequence of organisms. (OR)
Shows one succession of feeding relationships.
Example: Grass  Grasshopper  Lizard  Hawk

7. (5) Food Web
Shows the transfer of energy and matter between all of the different organisms within an ecosystem. (OR)
Shows all of the feeding relationships within an ecosystem.
Example:

8. (6) Trophic Levels 1st 2nd 3rd 4th
Trophic Level = Step in a food chain or food web.
1st Trophic Level = Producers / Autotrophs 2nd + Higher Trophic Levels = Consumers / Heterotrophs
Example: Grass  Grasshopper  Lizard  Hawk
1st
2nd
3rd
4th

9. (8) Energy Pyramids Shows:
Distribution of organisms throughout the trophic levels.
Amount of energy available at each level.
Only 10% of energy from one level transfers to the next level.
Lower Trophic Levels = More Energy
Higher Trophic Levels = Less Energy
Biomass: Quantity of living organisms within a level.
Lower Trophic Levels = Higher Biomass
Higher Trophic Levels = Lower Biomass

10. July 22, 2012
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