1. FLOW OF ENERGY AND NUTRIENTS WITHIN ECOSYSTEMS

2. Energy is involved in every activity on Earth

3. Photosynthesis and Cellular Respiration

4. Photosynthesis:
Plants transform light energy from the sun into chemical energy (glucose):
light energy + carbon dioxide + water → glucose oxygen

5. Cellular Respiration:
Most other living things transforms chemical energy (glucose) into useable energy:
glucose oxygen → carbon dioxide + water + useable energy

6. Autotrophs (Producers)
Get energy by making their own food (photosynthesis)
Heterotrophs ( consumers and decomposers) get energy by consuming other organisms.

8. Types of Heterotrophs :
Herbivore – eats only plants
Omnivore – eats producers and consumers
Carnivore – eats only other consumers
Decomposers –eat/ breakdown waste/dead organisms

9. How can we model the flow of energy in an ecosystem?
Food Chains
Food Webs

10. 1. Food Chain
A Food Chain is a model that describes how energy is passed from one living thing to another (one path).
Each step in a food chain is called a trophic level.

11. Trophic Levels in a Food Chain: Label your diagram
A secondary consumer can also be top predatory or tertiary consumer

13. Food Webs
Complex model that describes how energy in an ecosystem is transferred through two or more interconnected food chains (many paths).

14. Food Web

15. Food Web
Can an animal be both a secondary and tertiary consumer?

17. How does Energy Cycle in an ecosystem?
As each organism eats another, energy is transferred up the trophic level
When ANY organism dies, decomposers break it down and release any stored energy back into the earth.
What would the world be like without decomposers

18. Energy is lost in the Transfer (page 5)
Only a small amount (10%) of the energy transferred is available for the next trophic level  because most of the energy is used by organisms to live.  
consumers
10%
Producers
Between 80-90% of the energy is used for chemical reactions and is lost as heat.

19. Food Pyramid
A Food Pyramid models the loss of energy from one trophic level to another.
This means ecosystems can support fewer organisms at higher trophic levels, as less energy reaches these levels.
When one organism consumes another, the energy stored in the food organism is transferred to the consumer.

20. Practice
Food Chain WS