1

Energy Flow Through an Ecosystem

Food Chains, Food Webs, Energy Pyramids

2

•Begins with the SUN

•Photosynthesis

6CO2 + 6H2O + sunlight & chlorophyll C6H12O6 + 6O2

3

Photosynthesis•Chemical reaction where green plants use water & carbon dioxide to store the sun’s energy in glucose

•ENERGY is stored in glucose

•Glucose is stored as starch in plants

4

Organisms that can make glucose

during photosynthesis

are called PRODUCERS.

5

Producers use most of the energy they

make for themselves.

6

Producers use cellular

respiration to supply the

energy they need to live.

7

CELLULAR RESPIRATION is

the chemical reaction that releases the

energy in glucose.

6O2 + C6H12O6 -->  6H2O + 6CO2 + energy

The product that plants use from photosynthesis is:

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Oxyg

en

Starch

Gluco

se CO2

25% 25%25%25%

201 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 2

0

21 22 23 24 25 26 27 28 29 30

1.Oxygen2.Starch3.Glucose4.CO2

What is glucose stored as in plants?

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Cellulose

Glyc

ogen

Fructo

se

Starch

25% 25%25%25%

201 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

21 22 23 24 25 26 27 28 29 30

1.Cellulose2.Glycogen3.Fructose4.Starch

How is the energy in glucose released?

10

Photosyn

thesis ATP

Cellular

Respi...

Ferm

entation

25% 25%25%25%

1.Photosynthesis

2.ATP3.Cellular

Respiration4.Fermentatio

n

201 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

21 22 23 24 25 26 27 28 29 30

What is a waste product of respiration?

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Carbon dioxide

Oxyg

en

Wate

r

Gluco

se

25% 25%25%25%

201 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

21 22 23 24 25 26 27 28 29 30

1.Carbon dioxide

2.Oxygen3.Water4.Glucose

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The energy that is not used by

producers can be passed on to

organisms that cannot make their

own energy.

13

Organisms that cannot make their

own energy are called

CONSUMERS.

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Consumers that eat producers to get energy:

•Are first order (1st) or primary consumers

•Are herbivores (plant-eaters)

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Most of the energy the

primary consumer gets

from the producer is used by the consumer.

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Some of the energy moves

into the atmosphere as

heat.

17

Some energy in the primary consumer is

STORED & not lost to the atmosphere

or used by the consumer itself.

This energy is available for

another consumer (predator).

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A Consumer that Eats Another Consumer for

Energy:•Is called a secondary or 2nd order consumer

•May be a carnivore or a omnivore

•May be a predator

•May be a scavenger

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Most of the energy the secondary

consumer gets from the primary

consumer is used by the secondary consumer.

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Some of the energy is lost as heat, but some energy is stored and can passed on

to another consumer.

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A consumer that eats a consumer that already

ate a consumer:

•Is called a 3rd order or tertiary consumer

•May be a carnivore or a omnivore

•May be a predator

•May be a scavenger

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Consumers that eat producers & other

consumers

Are called

omnivores

Omnivores eat plants

and animals

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Consumers that hunt & kill other

consumers are called predators.

The animals that are hunted & killed are

called prey.

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Consumers that eat other dead

consumers are called scavengers

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The transfer of energy from the sun to producer to primary consumer then to higher order consumers can be shown in a FOOD

CHAIN.

All primary consumers are herbivores.

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True

False

50%50%

1.True2.False

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21 22 23 24 25 26 27 28 29 30

Organisms that can’t produce their own energy are:

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Autotro

phs

Produce

rs

Consumers

Trophics

25% 25%25%25%

1.Autotrophs2.Producers3.Consumers4.Trophics

201 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

21 22 23 24 25 26 27 28 29 30

What do scavengers eat?

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Plants

Inse

cts

Plants and Ani...

Dead O

rganisms

25% 25%25%25%

1.Plants2.Insects3.Plants and

Animals4.Dead

Organisms

201 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

21 22 23 24 25 26 27 28 29 30

Why don’t consumers get all of the energy the producers had?

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It would be to

...

Some is

lost

a...

They use it

fo...

No energy

flow

25% 25%25%25%

1.It would be too much

2.Some is lost as heat

3.They use it for reproduction

4.No energy flow

201 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

21 22 23 24 25 26 27 28 29 30

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Food Chains Show Available Energy

31

More Food Chains

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Another way of showing the transfer of energy in

an ecosystem is

theENERGY

PYRAMID

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Energy Pyramids Show •Amount of available energy decreases for higher consumers•Amount of available energy decreases down the food chain•It takes a large number of producers to support a small number of primary consumers•It takes a large number of primary consumers to support a small number of secondary consumers

34

35

Food Webs:

•Are interconnected food chains

•They show the feeding relationships in an ecosystem

36

How Many Chains are in this web?

37

Identify the Producers, Consumers, & Decomposers:

Count the Food

Chains!

38

Incre

ases

Decre

ases

Stays

the sa

me

None of t

he ab...

25% 25%25%25%

What happens to the amount of available energy as you move up a food chain?

1.Increases2.Decreases3.Stays the

same4.None of the

above

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21 22 23 24 25 26 27 28 29 30

How much energy is available for 2nd level consumers if producers have 5000 units?

39

5000500 50 5

25% 25%25%25%

1.50002.5003.504.5

201 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

21 22 23 24 25 26 27 28 29 30

What is the second level consumer?

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25% 25%25%25%

1.Flowers2.Snail3.Song bird4.Hawk

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21 22 23 24 25 26 27 28 29 30

What is the primary consumer?

41

Flower

Snail

Song bird

Hawk

25% 25%25%25%

1.Flower2.Snail3.Song bird4.Hawk

201 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

21 22 23 24 25 26 27 28 29 30 31 32 33

What organism is the autotroph?

42

Flower

Snail

Song Bird

Hawk

25% 25%25%25%

1.Flower2.Snail3.Song Bird4.Hawk

201 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

21 22 23 24 25 26 27 28 29 30 31 32 33

Which organism is the tertiary consumer?

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Flower

Snail

Song Bird

Hawk

25% 25%25%25%

1.Flower2.Snail3.Song Bird4.Hawk

201 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

21 22 23 24 25 26 27 28 29 30 31 32 33

Which organism is a herbivore?

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Flower

Snail

Song Bird

Hawk

25% 25%25%25%

1.Flower2.Snail3.Song Bird4.Hawk

201 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

21 22 23 24 25 26 27 28 29 30 31 32 33

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