Lesson 3 Energy in Ecosystems

Key Concepts/essential questions: How does energy move in ecosystems? How is the movement of energy in an ecosystem modeled?

Vocab Photosynthesis Chemosynthesis Food chain Food web Energy pyramid

Agree OR Disagree The sun is the source for all energy used by living things on Earth? All living things get their energy from eating other living things?

How does the grass get the energy it needs? The grass gets energy from sunlight and performs photosynthesis.

Producers What powers the process of photosynthesis? Light energy, usually from the Sun, powers photosynthesis.

WORD ORIGIN: photosynthesis… What words do you know that begin with photo? root -graph means "write” What is the meaning of photograph? A photograph is an image created using light energy How does light relate to photosynthesis? The energy from light powers the processes that create food through photosynthesis.

chemosynthesis What other words begin with chemo-? Chemotherapy??? What is the meaning of the word chemotherapy? medical treatment with chemicals look up the word chemotherapy in a dictionary to find the meaning of the root chemo-. look up the word synthesis.

synthesis means "to put together" or "to build.“ Chemosynthesis: to build, using chemicals What is the role of chemicals in chemosynthesis? They provide chemical energy. What is being built? food molecules

What materials do producers use to make food during chemosynthesis? Producers use chemical energy in inorganic compounds to make food during chemosynthesis.

Look at Figure 10 in text on pg. 724. What does the arrow tell you about where the plant gets carbon dioxide for photosynthesis? Carbon dioxide enters the leaf directly from the atmosphere What does the arrow tell you about where the plant gets water for photosynthesis? The water travels into the leaf from other parts of the plant (roots).

3 Energy in Ecosystems Lesson 3: Energy in Ecosystems-notes A. How does energy move in ecosystems? 1. Matter cycles through an ecosystem. 2. Energy flows through an ecosystem. 3. Energy can change form as it moves through an ecosystem, but the total amount of energy stays the same. This rule is called the law of conservation of energy.

4. Organisms that make their own food are producers. a. The process of photosynthesis uses light energy to make food and oxygen from carbon dioxide and water. b. Chemosynthesis is the process of making food using chemical energy instead of light energy.

5. Consumers obtain energy by eating other organisms. a. A(n) herbivore eats only plants. b. Carnivores are animals that eat other animals. c. Omnivores eat producers and other consumers. d. Consumers called detrivores (scavengers) eat dead organisms. e. Another name for bacteria and mushrooms is decomposers. f. Decomposers help cycle nutrients through ecosystems.

B. Modeling Energy in Ecosystems 1. As energy changes from one organism to another in an ecosystem, some stored chemical energy changes to thermal energy. 2. A(n) food chain is a model that shows how energy flows in an ecosystem through feeding relationships.

C. Food Webs 1. When you overlap the food chains in an ecosystem, the result is a(n) food web. 2. In a food chain and a food web, arrows show the movement of energy.

D. Energy Pyramids 1. A(n) energy pyramid shows the amount of energy available in each step of a food chain. 2. The steps of this energy model are called trophic levels. a. The bottom layer of an energy pyramid contains producers. b. The middle layer of an energy pyramid contains consumers that eat producers.

c. The top layer of an energy pyramid contains consumers that eat other consumers. 3. Only about 10 percent of the energy in one step of an energy pyramid transfers to the next higher step.

Brainpop http://connected.mcgraw-hill.com/media/repository/protected_content/COMPOUND/50000025/8/27/Photosynthesis_and_Respiration/00053412.htm?mghCourseID=J3B3WWJLT82D2DYG587957LKB4

Consumers Look at figure 12…. How does the worm get energy? It gets energy by consuming the remains of other animals and plants. How does the worm help the environment? By decomposing dead organisms, the worm helps keep the environment clean

Food Chains Look at figure 13…. What is a feeding relationship? It is an interaction between two organisms where one organism eats the other. Draw a food chain Share answers (discuss feeding relationship)

How does a food chain model energy flow? Arrows in a food chain show how energy is transferred from one organism to another through a feeding relationship.

In terms of school and science…What is a model? A model is a way of describing or showing an observation or process.

Food chain arrows that indicate the transfer of energy. What does the arrow below the hawk tell you about the energy transfer? Energy is transferred to the hawk when it eats another organism (snake) Why is there no arrow pointing away from the hawk? Because there is no organism shown that eats the hawk

Video clip http://connected.mcgraw-hill.com/c2j/syllabus.syllabusLesson.do?bookId=J3B3WWJLT82D2DYG587957LKB4&lessonId=7EOP91DMCXOL51SX6CP8JQP4QY (video 1)

Food Webs Look at Figure 14…. Try to make as many food chains using this web as you can

Video clip http://connected.mcgraw-hill.com/c2j/syllabus.syllabusLesson.do?bookId=J3B3WWJLT82D2DYG587957LKB4&lessonId=7EOP91DMCXOL51SX6CP8JQP4QY (video 2)

What models show the transfer of energy in an ecosystem? The transfer of energy in an ecosystem is shown with food chains and food webs. What kind of organism must be at the bottom of a food web? Why? A producer must be at the bottom of a food web because energy must flow into the food web from an outside source, such as the Sun.

Food Web Is the portion of the food web shown below a complete food chain? Explain. Yes, it includes producers(diatoms) and consumers. Do any organisms pictured in the portion of Figure 14 below get energy from the leopard seal? No If the leopard seal has no predators in a given area, do any organisms get energy from it? Yes, decomposers get energy from the leopard seal.

Energy Pyramids How does the amount of available energy change at each trophic level? The amount of available energy decreases at each trophic level. Which trophic level contains the fewest organisms? Why? Trophic level 3 contains the fewest organisms because it has the least energy available. What kind of organism is in trophic level 1? Trophic level 1 contains producers that get energy from an outside source, usually the Sun. *note fading blue arrow*

Video clip http://connected.mcgraw-hill.com/c2j/syllabus.syllabusLesson.do?bookId=J3B3WWJLT82D2DYG587957LKB4&lessonId=7EOP91DMCXOL51SX6CP8JQP4QY (video 3)

Questions What is an example of a producer in the trophic level at the bottom of the pyramid? Plants Can carnivores occupy trophic level 1? Explain. No, carnivores get energy by eating meat. The only available energy in trophic level 1 comes from the Sun.

Discussion What did you have for dinner last night? Use an energy pyramid to trace the flow of energy from the Sun to each kind of food.

Agree OR Disagree The sun is the source for all energy used by living things on Earth? Disagree. The sun in the main source of energy for most life on Earth; some producers, deep in the ocean, use chemical energy rather than light energy.

Agree OR Disagree All living things get their energy from eating other living things? Disagree. Many organisms get their energy by eating other organisms; some organisms are producers and get their energy through the process of chemosynthesis or photosynthesis to make their food.

Key Concepts/essential questions: How does energy move in ecosystems? Energy moves in a flow, How is the movement of energy in an ecosystem modeled? Arrows in a food chain show how energy is transferred from one organism to another through a feeding relationship. (food chain, food web, energy pyramid)

Discussion Question How does energy flow through an ecosystem?

Energy flow begins with energy in sunlight Energy flow begins with energy in sunlight. It is stored as chemical energy in plants. As animals eat plants, energy moves from the plant to the animal. As animals eat other animals, energy flows from the animal being eaten to the animal eating it. During each of these steps, energy can change form, such as changing from chemical to thermal energy.