1. Nutrition and Energy Flow
Feeding Relationships

2. Energy Anytime an organism eats, it’s doing two things:
consuming matter
obtaining energy

3. Energy
Studying FEEDING RELATIONSHIPS and ENERGY FLOW helps one understand how an ecosystem functions

4. Energy
In discussing the flow of energy, there are organisms that PRODUCE it and organisms that simply CONSUME it

5. Producers
Producers don’t actually make the energy, but they change its form
Convert solar energy into glucose and ATP
What type of organisms are producers?

6. Plants (w/ some exceptions)
Plants undergo PHOTOSYNTHESIS to convert solar energy into GLUCOSE.
GLUCOSE is later broken down to form ATP.
ATP = Adenosine Triphosphate
ATP is the energy molecule used by cells.

7. Producers Producers are also called AUTOTROPHS Auto = self
-troph = refers to nutrients

8. Consumers
Some organisms do not have the ability to use the suns energy to produce carbon based molecules and must eat other organisms in order to do so.
Consumers are called HETEROTROPHS
Hetero = other, different
-troph = refers to nutrients

9. Herbivores Heterotrophs that eat ONLY autotrophs are called HERBIVORES
Herbi = from herba - grass
-vore = from vorare, to devour

10. Heterotrophs that ONLY eat other heterotrophs are CARNIVORES
Carne = meat, flesh

11. Omnivores
Heterotrophs that eat BOTH autotrophs and other heterotrophs are OMNIVORES
Omni = all

12. Heterotrophs that are opportunistic and do not kill for food
Scavengers
Heterotrophs that are opportunistic and do not kill for food

13. Decomposers
Break down dead organisms into simpler molecules which are released back into the Earth.

14. Matter and Energy Flow
When you eat, you consume matter which cycles through an ecosystem from autotrophs to heterotrophs
You also capture some of the energy present in the food and some energy is lost as heat.

15. Models
In order to study and understand the flow of matter and energy, scientists use different models.

16. Food Chain The simplest model is a FOOD CHAIN.
It shows only one pathway that energy may be transferred.
It moves from autotrophs to heterotrophs

17. Food Chain Arrows are used to show the direction of energy flow.
If you are not sure, think of the arrows as meaning “...is eaten by...”

18. Construct a food chain...
Create a food chain using the following organisms

19. grass > grasshopper > sparrow > gopher snake> coyote

20. Food Webs
FOOD WEBS show all possible feeding relationships, i.e. every possible pathway for the transfer of matter and energy
A food web shows many food chains

21. Food Web

22. Food Webs
Food webs show ALTERNATIVE PATHWAYS - other possible pathways through which an organism can obtain energy

23. Alternative Pathways