1. Chapter 1 Lesson 3: Photosynthesis
page 53
This picture is from the Cumberland Gap in West Tennessee.

2. Factories
Leaf cells contain the most abundant type of factories in the world. Do you know what these factories manufacture?
These factories manufacture food and oxygen. In this lesson we will explore and discuss how leaves accomplish this.

3. Create the Foldable on page 61.
Photosynthesis
Leaves
Photosynthesis and Cellular Respiration
Energy Pyramid

4. What is Photosynthesis?
BrainPop- Photosynthesis
All living things need energy to survive. Animals eat food to get energy, and plants make their own food. But where do plants get the energy to make their own food?
Their energy comes from the sunlight.
Why do you think plants have leaves?
Plants use their leaves to absorb sunlight.

5. Photosynthesis What is photosynthesis?
Photosynthesis is the process of making food using sunlight.
Plants capture the energy of the light and trap it in the foods they make.
Photosynthesis occurs in cells that have chloroplasts.
This image is on page 54.

6. What is photosynthesis?
Sunlight, water, and carbon dioxide are needed to perform photosynthesis.
Plants take in energy from the sunlight, water, and carbon dioxide and produce oxygen and glucose or sugar.
Photosynthesis, Plant Growth and Changes
The Process of Photosynthesis

7. What do leaves do? Illuminating Photosynthesis Parts
Functions that lead to photosynthesis
Roots
absorb the water
Xylem
a tissue that carries water to the leaves
Stomata (stoma)
tiny pores that open and close letting in carbon dioxide and letting out oxygen; found on the underside of the leaf
Guard Cells
in charge of opening and closing the stomata; responds to the amount of water and light that the plant receives
Chloroplast
where photosynthesis occurs; located underneath the epidermis
Epidermis
the outermost area of the leaf
Cuticle
the waxy top of the leaf surface, prevents moisture from evaporating
Illuminating Photosynthesis

8. 6CO2 + 6H2O + ENERGY -> C6H12O6 + 6O2
What do leaves do?
Carbon Dioxide and water enter the chloroplasts and combine in the presence of light energy. This combination results in sugar and oxygen. The plant uses the sugars it produces as food. The sugars are transported to all of the plant’s cells by a type of tissue called phloem. Excess sugar is stored as starch, which the plant can break down for food. Most oxygen exits the plant through the stomata as a waste product.
Discuss the Main Idea
Review with students the main functions of plant leaves. Ask:
How is the color of a plant leaf related to its function?
Cells in a plant leaf contain green structures called chloroplasts that make food for the plant.
Why aren’t the roots of a plant green like the stem and leaves?
The roost are underground and not exposed to sunlight. Roost are responsible for absorbing water and minerals, not making food for the plant.
How are the guard cells related to the stomata?
The guard cells surround the stomata and control the opening and closing of the stomata.
Develop Vocabulary
stomata Explain that stomata are the tiny pores usually found on the underside of leaves. They open and close to give off and take in gases.
Quick Check
Draw Conclusions: Suppose you did not water a plant for two weeks. Would do you expect the stomata to be open or closed?
The stomata would be closed to prevent water loss.
Critical Thinking: Identify the cell structures that enable plants to conduct photosynthesis.
chloroplasts.
6CO2 + 6H2O + ENERGY -> C6H12O6 + 6O2

9. 6CO2 + 6H2O + ENERGY -> C6H12O6 + 6O2
Carbon Dioxide + Water+ Energy -> (Produces) sugar and oxygen
This equation shows how the materials of photosynthesis react with one another and what they produce.
Review
Suppose you did not water a plant for two weeks. Would you expect the stomata to be open or closed?
The stomata would be closed to prevent water loss.
Identify the cell structure that enable plants to conduct photosynthesis?
chloroplasts

10. What is the photosynthesis and respiration cycle?
All living things need energy to carry out their life processes.
The photosynthesis and respiration cycle provides energy to plants and animals.
Discuss the Main Idea
Explain to students that the basic food plants produce is called a carbohydrate. When people eat plants, they are eating carbohydrates. Explain that the other main food groups also produced by plants are proteins, fats, vitamins, minerals, and water. Ask:
What happens when light strikes a green leaf?
Plant cells make food.
Why is it important for people to eat food from every major food group?
to get the materials they need for growth and health
Develop Vocabulary
carbohydrate - Word Origin Explain to students that the word carbohydrate comes from the Latin carbo for carbon and hydrate, which signifies hydrogen and oxygen (or water). Carbohydrates are a major food group. Have students list foods that contain carbohydrates. Possible answers: bread, rice, pasta, cereal, potatues, peas, corn, fruit, fruit juice, milk, yogurt, cookies, candy, and soda
cellular respiration - Explain to students that the words cellular respiration describe the process of respiration that occurs in a plant’s cells. Ask students to tell what substances are released by the cell during cellular respiration. Answer: Carbon dioxide and water are released.
Quick Check
Draw Conclusions: In what ways to animals depend on plants?
Plants, or the animals who eat plants, supply other animals with the carbohydrates they need to survive.
Critical Thinking: Is there more energy in the plant before or after photosynthesis?
There is more energy stored in the plant after photosynthesis.

11. What is the photosynthesis and respiration cycle?
The photosynthesis and respiration cycle provides energy to plants and animals.
The sugar that the plants produce is a carbohydrate. A carbohydrate is the name given to a group of substances made from carbon, hydrogen, and oxygen. Simple carbohydrates can be stored as food or modified to make structural materials. When plants store sugar, they usually store it as starch. The cell walls of plant cells are made of cellulose. Starch and cellulose are complex carbohydrates made of thousands of simple sugar units.

12. What is the photosynthesis and respiration cycle?
Look at the image on page 58 again.
Animals depend on photosynthesis for their source of energy. When an animal eats a plant, it takes in the carbohydrates stored in the plant. Even if the animal is a carnivore and eats other animals, they are taking in the carbohydrates that these animals gained from eating a plant in the first place.

13. What is the photosynthesis and respiration cycle?
The oxygen that animals produce during photosynthesis is breathed in by animals during respiration. Some of the oxygen is also used by plants. When plant or animal cells need energy, they can get it from stored carbohydrates. The energy in carbohydrates is released when the cells of organisms use oxygen to break down the sugars in the process called cellular respiration.

14. What is the photosynthesis and respiration cycle?
You can think of respiration and photosynthesis as the opposite of each other. During cellular respiration, plant and animal cells produce carbon dioxide and water, which are then released back into the air. Plants use the carbon dioxide along with water to produce sugars during photosynthesis. And the cycle begins again.

15. Review In what ways do animals depend on plants?
Plants, or animals who eat plants, supply other animals with the carbohydrates they need to survive. Animals also rely on plants for oxygen.
Is there more energy in the plant before or after photosynthesis?
There is more energy store in the plant after photosynthesis.

16. What are energy pyramids? page 60
Only about 10% of the Sun’s energy gets turned into food energy by a producer. Energy pyramids show that it takes a huge number of organisms to support an ecosystem. The bottom of the pyramid represents producers, the largest level. It is the largest level because it contains the most organisms and therefore the most energy. There are fewer numbers of organisms and less available energy at each ascending level of the pyramid.
About 90% of the energy is lost at each level. Each level only uses 10% of the energy from the level before.
Discuss the Main Idea
To help students better understand the concept of energy loss at each higher level of an energy pyramid, put out a bowl with 100 marbles, buttons, or other small objects. Tell students that 10 percent of 100 is 10. Have a student volunteer remove 10 marbles. Ask:
If 90 percent of the 10 marbles are removed, how many marbles are left?
Answer: 1
How does this demonstration r elate to how energy is transferred in an energy pyramid?
Each level of an energy pyramid receives only 10 percent of the energy from the level below it.
Develop Vocabulary
energy pyramid Draw an example of an energy pyramid on the board, making sure to include at least four levels. From the bottom level to the top, label them producers, herbivores, omnivores and carnivores, and top carnivore. Explain that each of an ecosystem’s organisms has a certain place in an energy pyramid.
Quick Check
Draw Conclusions: What can you conclude about the number of hawks in a forest if the mice population it preys upon is decreasing?
it would decrease
Critical Thinking: In a prairie ecosystem, would you expect a rabbit or a hawk population to be larger? Explain.
Since rabbit are herbivores, the rabbit population should be much larger. Hawks are top carnivores.

17. Review
What can you conclude about the number of hawks in a forest if the mouse population they prey upon is decreasing?
If the mouse population is low, than we can conclude a large hawk population is reducing their numbers. If the mouse population is decreasing, eventually the hawk population will decrease as well.
In a prairie ecosystem, would you expect a rabbit or a hawk population to be larger?
Since rabbits are herbivores, the rabbit population should be much larger.

18. Review Photosynthesis Facts Magic School Bus Review
I know that- Photosynthesis
Photosynthesis