Chapter 5: How Ecosystems Work

​5.1 Energy Flow in Ecosystems

Organisms need energy to survive, grow, and reproduce. What are the sources of this energy, and how does energy flow through the entire system?

Poll

The ultimate source of energy for nearly every organism on Earth is/are...

• the plants in the ecosystem.

• microscopic organisms like plankton and bacteria.

• the sun.

• the largest organisms in an ecosystem since they are the top fo the food chain.

Energy from the sun enters an ecosystem when organisms perform photosynthesis.

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*Energy can't be created or destroyed, but it CAN be transformed!

Life depends on the sun.

*Matter can't be created or destroyed, but it CAN be reused.

During photosynthesis light energy is captured by organisms to convert water and carbon dioxide into sugar and oxygen.

Multiple Choice

What are the inputs of photosynthesis?

• carbon dioxide and oxygen

• water and sugar

• water and carbon dioxide

• oxygen and water

Multiple Choice

What are the outputs (products) of photosynthesis?

• oxygen and carbon dioxide

• oxygen and sugar

• oxygen and water

• sugar and carbon dioxide

Different organisms use and store carbohydrates in different ways.

Carbohydrates are energy rich molecules that organisms use to perform life processes.

​Since not all organisms can produce carbohydrates, energy from one organism is transferred to another when one organism consumes another.

Multiple Choice

Which food would you expect to provide the greatest amount of carbohydrates?

• Potato

• Fish

• Chicken

• Celery

Also called autotrophs because

they "make their own food".​

• auto = "self"

• troph = "feeding"​

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Not all autotrophs are plants!!

Producers are typically organisms capable of photosynthesis.

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Chemosynthesizers use other molecules as a source of energy to produce carbohydrates.

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e.g. Sulfur-metabolizing bacteria in hydrothermal vents and iron-metabolizing bacteria in our neck of the woods.

​Not all organisms require sunlight to make their own food.

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Organisms that get their energy by feeding on other organisms. ​

Consumers

​Consumers that get their energy by breaking down organic matter from dead organisms.

Decomposers

Consumers that eat only plants.

​​Herbivores

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​Consumers that eat only meat.

​​Carnivores

​Consumers that eat both plants and meat.

​Omnivores

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Multiple Choice

What is an example of an important role an herbivore plays in an ecosystem?

• They keep the top predator populations well fed.

• They capture energy from the sun and make food for other organisms.

• They help further the break down decaying material.

• They help prevent overgrowth of vegetation.

Multiple Choice

Under which category would this organism fall?

• decomposer

• herbivore

• omnivore

• carnivore

Multiple Choice

Under which category would this organism fall?

• Herbivore

• Carnivore

• Omnivore

• Decomposer

Multiple Choice

Which is NOT a type of consumer?

• producer

• decomposer

• carnivore

• herbivore

This is NOT the same as breathing!!​ But they are connected...

Cellular respiration is the process of breaking down carbohydrates to yield energy.

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Open Ended

What is the connection between photosynthesis and cellular respiration??

The products of one process become the reactants in the other.

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Multiple Select

Which organism(s) perform cellular respiration? (Select all that apply)

• Plants

• Algae

• Fish

• Humans

Complete the Active Reading Worksheet

Food chain trace the flow of energy within an ecosystem.

A chain becomes a WEB when it includes more feeding relationships.​

Trophic Levels

​Some text here about the topic of discussion.

Energy Pyramids