Energy Flow in Ecosystems Environmental Science Chpt 5 Section 1

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

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

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

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

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

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

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

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