1. Energy Flow in Ecosystems
Environmental Science
Chpt 5 Section 1

2. Life depends on the sun
Energy from the sun enters an ecosystem when a plant uses sunlight to make sugar molecules in a process called photosynthesis.
Plants, algae and some bacteria preform photosynthesis
6CO2 + 6H2O + Solar energy  C6H12O6 + 6O2

3. Flow of energy in the ecosystem
Producer: an organism that makes its own food
Also known as autotrophs
Most get energy directly from the sun

4. Flow of energy in an ecosystem
Consumer: an organism that get their energy by eating other organisms
Also known as heterotrophs
Get their energy from the sun indirectly by eating producers

5. What eats what?
Herbivores – consumers that eat only producers (are plant eaters)
Carnivores: consumers that eat only only other consumers (called flesh-eaters)
Omnivores – consumers that eat both producers and other consumers (called eaters of all)
Decomposer: a consumers who get their food by breaking down dead organisms

6. How do organisms use this food?
Cellular respiration: the process of breaking down food to produce energy
C6H12O6 + 6O2  6CO2 + 6H2O + energy

7. Food chain
A food chain is a sequence in which energy is transferred from one organism to the next as each organism eats another organism

8. Food web
A food web shows many feeding relationships that are possible in an ecosystem

9. Trophic level
Each step through which energy is transferred in a food chain is known as a trophic level