1. Energy Dissipation and Cycles

2. A Cycle

3. Nutrients: all the chemical substances that the body needs to stay alive.
-- Two examples are carbon, and nitrogen
C N
Like water, nutrients are passed between organisms and the environment through biogeochemical cycles.

4. Producers (autotrophs) convert the sun’s energy into glucose (food)
CO2 + H2O → C6H12O6 + O2
When there is no light available, some organisms can use chemicals to produce glucose and this process is called chemosynthesis.
Consumers (heterotrophs) obtain chemical energy by eating producers or other consumers.
Decomposers break down wastes and dead organisms.

5. The sun provides Energy to autotrophs
The sun provides Energy to autotrophs
Producers use this Energy to make food (glucose)
90% of this Energy is used by the producer to survive
(therefore is “used up” by the producer)
10% of this energy is used for the plant to grow… so there is more biomass (more to eat)
 This is the Energy that can be passed on to the consumer…

6. Food Chain or Food Web? Food Chain:
A food chain is the direct path of food from a producer to a final consumer
grass ---> grasshopper --> mouse ---> snake ---> hawk
Food Web:
A food web consists of interlocking food chains.

7. Chain or Web?

8. Chain or Web?

10. Steps in a food chain or food web are called trophic levels
Only 10% of the energy from one trophic level goes on to the next trophic level

12. Energy does not recycle!!
But matter does
Can you explain this diagram?

14. Types of Heterotrophs or Consumers
Herbivores: eat only plants (producers)
Carnivores: only eat animals (consumers)
Omnivores: eat both plants and animals
(producers and consumers)

15. Consumer names by position in a Food Chain

17. Patterns of Chemical Cycling
Producers incorporate chemicals from the non-living environment into organic compounds (biomass)
Consumers eat producers and then decomposers break down the biomass into non-living chemicals again.
Non-living processes also intervene (such as fires and rain).

18. The Carbon Cycle
                                                                                                                                                                           

19. The Nitrogen Cycle
                                                                                                                                                                           
Nitrogen Fixation Simplified

20. The Water Cycle
                                                                                                                                            

21. Can you explain this diagram?