Name:
Science: Photosynthesis
Date:
HR:
#7.1
Number:
Objective: I can explain photosynthesis.
DO NOW
1. Photosynthesis occurs in which organelle?
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2. Which variable does the experimenter change?
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3. Which variable does the experimenter measure?
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4. What is an example of Newton’s third law of motion?
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5. Why are igneous rocks often found on the ocean floor?
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6. LAW OF CONSERVATION OF ENERGY: energy cannot be ________________________
or
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HOMEWORK REVIEW
1. Question: Is Mr. Crowe’s classroom noisier when he leaves the room?
Independent variable
Dependent variable
Controlled variable
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2. Would the results to your experiment be valid if you added another adult to the
classroom only when Mr. Crowe is outside the room? Why or why not?
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3. Question: How quickly do AA batteries drain in different devices?
Independent variable
Dependent variable
Controlled variable
Objective: I can explain photosynthesis.
CELL ENERGY
Why do you get hungry?
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All cells need energy to live, grow, and reproduce. Plant cells get their energy from the
_____________. Many animals cells get the energy they need from
_____________________.
From Sun to Cell
Nearly all of the energy that fuels life comes from the sun. Plants capture energy from the
sun and change it into food through a process called photosynthesis. The food that plants
make supplies them with energy. This food also becomes a source of energy for the
organisms that eat the plants.
1. What is photosynthesis?
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REVIEW FROM 6TH GRADE:
Plants are called ____________________________, because
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Animals and decomposers are called __________________________, because
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Photosynthesis
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Plant cells have molecules that absorb light energy. These molecules are called pigments.
Chlorophyll, the main pigment used in photosynthesis, gives plants their green color.
Chlorophyll is found in chloroplasts.
2. What is chlorophyll?
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Twig video – PHOTOSYNTHESIS
1. Plants are able to make their own food using what three things?
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2. Where does water enter a plant?
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3. How does carbon dioxide enter the plant?
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4. Why is chlorophyll important?
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5. What two things does photosynthesis produce?
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6. Which one is waste?
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7. What is the equation for photosynthesis?
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8. Why is photosynthesis perhaps Earth’s most important chemical reaction?
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Plants use the energy captured by chlorophyll to change carbon dioxide and water into
food. The food is in the form of the simple sugar glucose. Glucose is a carbohydrate.
When plants make glucose, they convert the sun’s energy into a form of energy that can
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be stored. The energy in glucose is used by the plant’s cells. Photosynthesis also produces
oxygen. Photosynthesis is summarized in the figure below.
3. What is glucose?
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Chemical Reactions
Photosynthesis is a chemical reaction. A chemical reaction is a process that leads to the
transformation of one set of chemical substances into another. Chemical substances are
forms of matter that have constant chemical compositions (made of the same things) and
characteristics. They cannot be separated by physical means (melting, freezing, etc.).
Reactants and Products
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In a chemical reaction, the chemicals that change into something else are called the
reactants. At the end of the chemical reaction, the reactants have changed into different
chemical substances called products.
4. What is the difference between reactants and products in a chemical reaction?
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7. Write the equation for photosynthesis in the blank spaces below. There should be three
reactants and two products. Insert the reactants on the left side of the arrow and the
products on the right.
8. What are the reactants of photosynthesis?
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9. What are the products of photosynthesis?
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7. Explain in a paragraph how photosynthesis works. Your answer should include the
following terms: reactants, products, oxygen, chloroplast, carbon dioxide, chlorophyll, water,
glucose, light energy.
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