Organism Interactions
and
Energy Connections
Energy Connections
• All living things need energy to survive.
What is energy?
• The energy living things need comes from
carbon-compounds, or organic compounds.
– Organic compounds: molecules that contain a
carbon atom
• Carbohydrates: glucose, starch, cellulose (mostly
plants)
• Proteins: the muscles of animals (steak!)
• Fats: in muscle of animal tissues (fatty steak!)
Food Chains
• A food chain shows the flow of energy
between the organisms in an environment
Food Chains
• Notice that the arrow points from the
organism being eaten to the organism that
eats it.
– Like the burger you eat goes into you
Plants  Cow (burger)  Human
What do the arrows in the food chain
below indicate?
A. Sunlight
B. Energy flow
C. Heat transfer
D. Toxins
What do the arrows in the food chain
below indicate?
Energy flow
Food Webs
• When we put many food chains together in
one ecosystem, it is called a food web.
Energy Moves in a Food Web
Other animals get
energy from the fat
and protein in
other animals
Some animals
get energy
from plants
Plants make
glucose
from light
There are two groups that organisms are
divided into in any ecosystem based
upon how they obtain energy.
----------------- use sunlight directly to make
their own food.
Producers- use sunlight directly to
make their own food.
PHOTOSYNTHETIC
Parts of a Food Web
• Where are the producers in the food web
below?
Two groups of organisms based on
energy consumption.
Producers- use sunlight directly to make
their own food.
---------------- Organisms that eat producers
or other organisms for energy.
Consumers- Organisms that eat
producers or other organisms
for energy.
Two groups of organisms based on
energy consumption.
Producers- use sunlight directly to make
their own food.
Consumers- Organisms that eat producers
or other organisms for energy.
Parts of a Food Web
• Where are the consumers in the food web
below?
Consumers are Divided into Five
Categories
•
----------------consumer that eats
plants.
Consumers are Divided into Five
Categories
•
•
Herbivore
consumer that eats
plants.
---------------consumer that eats
animals.
Consumers are Divided into Five
Categories
•
•
•
Herbivoreconsumer that eats
plants.
Carnivoreconsumer that eats
animals.
---------------consumer that eats
both plants and
animals.
Consumers are Divided into Five
Categories
•
•
•
Herbivoreconsumer that eats
plants.
Carnivoreconsumer that eats
animals.
Omnivore
consumer that eats
both plants and
animals.
Consumers are Divided into Five
Categories
•
-----------------animals that feed
on the bodies of
dead animals.
Consumers are Divided into Five
Categories
•
•
Scavengersanimals that feed
on the bodies of
dead animals.
____________ organisms that get
their energy by
breaking down the
remains of dead
organisms.
Consumers are Divided into Five
Categories
•
•
Scavengersanimals that feed
on the bodies of
dead animals.
Decomposers organisms that get
their energy by
breaking down the
remains of dead
organisms.
Decomposers
• Are essential to any
ecosystem because
they are nature’s
recyclers.
Decomposition
Two groups of organisms based on
energy consumption.
Producers- use sunlight directly to make their own
food.
Consumers- Organisms that eat producers or
other organisms for energy.
–
–
–
–
–
Herbivores
Carnivores
Omnivores
Scavengers
Decomposers
Energy Pyramids
Energy Pyramids are diagrams shaped like
a triangle that shows the loss of energy at
each level of the food chain.
Energy Pyramid Labels
Tertiary
Consumers
Secondary
Consumers
Primary
Consumers
Each Level is called a Trophic
Level and represents the total
amount of available energy AND
biomass in each level.
How many trophic levels
are represented?
4
Why not more?
Producers
Tertiary Consumer
Secondary Consumer
Primary Consumer
Producer
• Trophic levels represent a
feeding step in the
transfer of energy and
matter in an ecosystem.
Each Trophic Level is the
total amount of energy
and biomass in all
organisms at one level in
the food web.
• Biomass- the amount of
organic matter (nutrients)
comprising a group of
organisms in a habitat.
Energy Pyramids
• Only energy stored in tissues
of an organism can be
transferred to the next level.
Less Energy
• As you move up a food chain,
both available energy and
biomass decrease.
• Energy and biomass are
transferred upwards but are
diminished with each transfer.
The higher up in the pyramid
an organism is, the more they
must eat to obtain energy.
More Energy
Energy Flow
Energy Transfer (percents)
0.1%
1%
10%
100%
• We can say that the
energy transfer from
level to level is
inefficient
– (not a lot of the energy
at each level makes it
up)
Energy Transfer (calories)
1 calorie
10 calories
100 calories
1,000
calories
• This means that there
can’t be many levels
in a food web or
pyramid
– The amount of energy
decreases, and it
cannot typically
support organisms at
higher levels than
tertiary consumer
1. Why is there a limited number of
energy levels in an energy pyramid or
food web?
A. Energy transfer is very efficient
B. Energy is captured as heat
C. Energy transfer is inefficient
D. Energy is not transferred in a food web
2. How is energy stored and transferred
in an ecosystem?
A. In light
B. In oxygen and carbon dioxide
C. In carbon compounds like glucose
D. In the process of decomposition
3. Which of the following organisms is a
primary consumer in the ecosystem
shown?
A. Hawk
B. Rabbit
C. Mountain lion
D. Frog
Population Impacts in a Food Web
• If the population of organisms at any level
of the food web changes, it will affect the
population at other levels
Population Impacts in a Food Web
• If the population of producers decreases,
then the population of primary consumers
will decrease if they don’t have enough
food.
Population Impacts in a Food Web
• If the population of primary consumers
decreases, then…
– The producers will increase because there are
less consumers eating them
– The secondary consumers will decrease
because there is less food for them
Which organism would be most affected if
the cricket population decreased?
A. Snake
B. Deer
C. Frog
D. Hawk
How does energy enter the food
web?
Better question… where does the
weight of a producer come from?
How does this...
this?
become
Photosynthesis
• Photosynthesis: a process that occurs in
producers and converts light, carbon
dioxide, and water into glucose (sugar)
and oxygen.
Carbon
Dioxide
Water
Sunlight
Glucose
Oxygen
More Photosynthesis
a. Photosynthesis removes carbon
dioxide from the air.
b. The carbon dioxide in the air is the
building block for glucose.
c. The light energy helps bond CO2
and H2O together to make glucose.
The Carbon Cycle
Carbon Cycle
• Carbon is found throughout the
environment
– Carbon is found in the atmosphere and in
water as carbon dioxide (CO2)
– Carbon is found in organisms as organic
molecules, like glucose (sugars) and fats
– Carbon is found buried in the ground as fossil
fuels
Carbon Cycle
• Carbon is cycled, or moves
1) Atmosphere: Carbon is in the form of CO2
CO2
Carbon Cycle
2) Producers: Use photosynthesis to make
sugars from CO2 in the atmosphere (carbon is
moved!)
C6H12O6
Carbon Cycle
3) Consumers: Eat organic molecules and
release CO2 into the atmosphere during
respiration, or die and go into the soil
CO2
Carbon Cycle
4) Soil: decomposers break down organisms,
releasing carbon into the atmosphere OR
trapping it in the ground (fossils)
Carbon Cycle
5) Fossil Fuels: carbon from some dead
organisms are trapped as fossil fuel until we
burn it
Pop Quiz Time: Hope you were paying
attention
Get out a clean sheet of paper and
number it 1 -10
1. What do the arrows in the food chain
below indicate?
A. Sunlight
B. Energy flow
C. Heat transfer
D. Toxins
2
. The diagram below represents a
a. Food chain
b. Food Web
c. Energy Pyramid
d. Nutrition web
3. Which of the following organisms is a
primary consumer?
a. Mouse
b. Snake
c. Mountain Lion
d. Frog
4. What is the source of energy for all the organisms
below?
A. The Hawk
B. Grass
C. Decomposers
D. Sun
5. At what level is there the LEAST
amount of available energy?
D
C
B
A
6. Which organism would be most
affected if the cricket population
decreased?
A. Snake
B. Deer
C. Frog
D. Hawk
7. How does energy enter a food chain?
A.The process of cellular respiration
B. The process of photosynthesis
C. Decomposers make the energy
D. None of the above
8. Where do plants get Carbon molecules
needed for photosynthesis?
a.
b.
c.
d.
From the earth
From the atmosphere
By breaking down dead organisms
From the sun
9. An iguana that feeds on
cabbage, carrots, crickets, and
meal worms as a regular diet
would be considered a
A.Carnivore
B.Herbivore
C.Omnivore
D.Decomposer
10. What term describes the organism
below?
A.Scavenger
B.Decomposer
C.Producer
D.Herbivore