Organism Interactionsand

Energy Connections

Energy Connections

• All living things need energy to survive.

What is energy?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 ChainsFood Chains

• A food chain shows the flow of energy between the organisms in an environment

Food ChainsFood 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 What do the arrows in the food chain below indicate?below indicate?

A. Sunlight

B. Energy flow

C. Heat transfer

D. Toxins

What do the arrows in the food chain What do the arrows in the food chain below indicate?below indicate?

Energy flow

Food WebsFood Webs

• When we put many food chains together in one ecosystem, it is called a food web.

Energy Moves in a Food WebEnergy Moves in a Food Web

Plants make glucose from light

Some animals get energy from plants

Other animals get energy from the fat and protein in other animals

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.

Parts of a Food WebParts 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 WebParts 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

• Herbivore- consumer that eats plants.

• Carnivore- consumer that eats animals.

• ---------------- consumer that eats both plants and animals.

Consumers are Divided into Five Categories

• Herbivore- consumer that eats plants.

• Carnivore- consumer 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

• Scavengers- animals 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

• Scavengers- animals 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 PyramidsEnergy Pyramids

Energy Pyramids are diagrams shaped like a triangle that shows the loss of energy at each level of the food chain.

Energy Pyramid

There are typically only 4 trophic levels in an energy pyramid

• Producers: organisms that convert the sun’s energy into organic compounds

• Primary consumers: organisms that eat producers to obtain energy compounds

• Secondary consumers: organisms that eat primary consumers for energy

• Tertiary consumers: organisms that eat secondary consumers for energy

Energy Pyramid LabelsEnergy Pyramid Labels

Producers

Tertiary Consumers

Primary Consumers

Secondary Consumers

• 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 PyramidsEnergy Pyramids

• Only energy stored in tissues of an organism can be transferred to the next level.

• 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

Less Energy

Energy Flow

Energy Transfer (percents)Energy Transfer (percents)

100%

0.1%

10%

1%

• 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)Energy Transfer (calories)

1,000 calories

1 calorie

100 calories

10 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

Why are there a limited number of energy Why are there a limited number of energy levels in an energy pyramid or food web?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

Producer

Primary Consumer

Secondary Consumer

Tertiary Consumer

How is energy stored and transferred in How is energy stored and transferred in an ecosystem?an ecosystem?

A. In light

B. In oxygen and carbon dioxide

C. In carbon compounds like glucose

D. In the process of decomposition

Which of the following organisms is a Which of the following organisms is a primary consumer in the ecosystem primary consumer in the ecosystem

shown?shown?

A. Hawk

B. Rabbit

C. Mountain lion

D. Frog

Population Impacts in a Food WebPopulation 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 WebPopulation 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 WebPopulation 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 Which organism would be most affected if the cricket population decreased?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... become this?

Photosynthesis

• Photosynthesis: a process that occurs in producers and converts light, carbon dioxide, and water into glucose (sugar) and oxygen.

Carbon Dioxide

Water Glucose OxygenSunlight

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 energy in light is now stored in the glucose molecule

Light CO2 H2O

Glucose O2

Starch

Fat(nuts)

How do consumers get energy?

Consumers eat other organisms to obtain organic molecules, which are forms of stored energy.

During cellular respiration, consumers release the energy stored in the bonds of the organic molecules.

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 moves1) Atmosphere: Carbon is in the form of CO2

COCO22

Carbon Cycle

2) Producers: Use photosynthesis to make sugars from CO2 in the atmosphere (carbon is moved!)

CC66HH1212OO66

Carbon Cycle

3) Consumers: Eat organic molecules and release CO2 into the atmosphere during respiration, or die and go into the soil

COCO22

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 1. What do the arrows in the food chain below indicate?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.Mouseb.Snakec.Mountain Liond.Frog

4. What is the source of energy for all the organisms below?

A. The HawkB. GrassC.DecomposersD.Sun

5. At what level is there the LEAST amount of available energy?

A

B

C

D

6. Which organism would be most 6. Which organism would be most affected if the cricket population affected if the cricket population

decreased?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. From the earthb. From the atmospherec. By breaking down dead organismsd. From the sun

9. An iguana that feeds on cabbage, carrots, crickets, and meal worms as a regular diet would be considered a

A.CarnivoreB.HerbivoreC.OmnivoreD.Decomposer

10. What term describes the organism below?

A.ScavengerB.DecomposerC.ProducerD.Herbivore

How many food chains?

Food Chains

• Food chains can be misleading because organisms very rarely eat only one other organism.

• Food webs show the many pathways of energy flow.

Food chain Food web(just 1 path of energy) (all possible energy

paths)

Think about our Ecosystem

• What animals and plants are in a food web in our ecosystem?

Toxins in food chains-

While energy decreases as it moves up the food chain, toxins increase in potency.

•This is called biological magnification

Ex: DDT & Bald Eagles