Energy is Transferred!

1ST Energy Transfer

SUN AUTOTROPH

2ND Energy Transfer

HETEROTROPH

3RD Energy Transfer

HETEROTROPH HETEROTROPH

4TH Energy Transfer

HETEROTROPH HETEROTROPH

5TH Energy Transfer???

HETEROTROPH HETEROTROPHFungi are Decomposers

FOOD WEB

a network of

connected food chains

TROPHIC LEVELS = steps in a food chain

• 1st trophic level is the producer • 2nd trophic level is the primary

consumer or herbivore• 3rd level is the secondary consumer or

smaller carnivore• 4th level is the tertiary consumer or

larger carnivore

Trophic Level# of energy transfers from sun to organism

(i.e. each step in a food chain)

Energy Flow is Inefficient

~17% energy stored as fat

~48% energy is lost as HEAT

~35% energy becomes waste

What’s left?

Only 10% of energy from previous trophic level is available to next level as food or biomass. This is known as the 10% law.

So, if I start with

• 1000 units of energy in my producer trophic level,

• What units of energy are available at each trophic level?

Pyramid of EnergyPYRAMID OF ENERGY

CYCLE

Matter is re-cycled! Molecules

are simply rearranged as they are made and

broken down.

Water Cycle• Precipitation/Condensation• Absorption (roots,

groundwater/soil, plant leaves)• Transpiration (through stomata

in plant leaves).• Evaporation (heat)• BRAIN POP

Brain Pop Videos

• http://www.brainpop.com/science/energy/energypyramid/

• http://www.brainpop.com/science/ecologyandbehavior/foodchains/