Colorado Agriscience Curriculum
Section:
Plant & Soil Science
Unit:
Plant physiology and growth
Lesson Title:
Lesson 5: Exploring Photosynthesis
Colorado Agricultural Education Standards:
AGS11/12.4
AGS11/12.4.7
11 & 12
Understand photosynthesis and respiration.
Colorado Science Standards:
SCI3.2.1 Science
comparing and contrasting the processes of photosynthesis and
respiration
SCI3.2.2 Science
explaining how simple molecules can be built into larger molecules
within organisms
SCI3.2.3 Science
explaining how large molecules are broken down into smaller molecules,
serving as an energy source or as basic building blocks in organisms
Student Learning Objectives (Enablers)
As a result of this lesson, the student will …
1. Students will be able to explain the process of photosynthesis
Time: Instruction time for this lesson: 50 minutes.
Resources:
Modern Biology, Holt, Rinehart and Winston
Agriscience Fundamentals and applications, Cooper and Burton
Tools, Equipment, and Supplies
Fruit for each student i.e. strawberries
Copy of PSS.1.PR handout for every student
Key Terms. The following terms are presented in this lesson and appear in bold italics:
Photosynthesis
Chloroplasts
Stomata
Glucose
Interest Approach
Photosynthesis in its simplest form is to convert carbon dioxide and water into
Unit 2, Lesson 5: Exploring Photosynthesis
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Sugar/carbohydrates and oxygen, and respiration is the opposite reaction. Therefore, students
will practice respiration first and explain their role and the plants’ role in creating homeostasis.
Do this by giving each student a fruit, (preferably with a noticeable amount of sugar. i.e.
strawberries). After students each eat a piece of fruit, have them exercise for three minutes. By
doing this, they will be releasing water through sweat and carbon dioxide while breathing. This
exercise will take approximately 10 minutes.
Students, we are going to start today by helping contribute to the plants in our area. So everyone
take one piece of fruit and eat it. Now that you have eaten your one piece, we are going to do a
light workout. On the count of three, you are going to do jumping jacks, and when I say stop you
will stop exercising and sit back down in your seats. Ready? One, Two, Three.
Allow students to exercise for about three minutes.
STOP! …. Thank you. Now how did that help plants?
Allow students to try to answer.
What we did by eating sugar and exercising is known as “respiration.” By eating the sugar in the
fruit and breathing in oxygen, we were able to produce something necessary for plant life. Does
anyone know what it is?
Allow students to try to answer.
By using sugar and oxygen, we were able to produce carbon dioxide and water. This as I said
previously is respiration. Since we do that for plants what do they do to produce sugar and
oxygen for us?
Allow students to try to answer.
Very good! Photosynthesis.
Summary of Content and Teaching Strategies
Objective 1. Students will be able to explain the process of photosynthesis
Review PowerPoint Slides 2-5 using a Little Professor Moment making sure the students capture
the information in their notes.
Slide 2
• I. Photosynthesis is the manufacture of food by plant cells.
– A. Sugar is the major product of photosynthesis and provides energy for the plant.
– B. There are two phases to the photosynthesis process.
• 1. Energy gathering—Plant leaves soak up sunlight.
• 2. Sugar making—Plants convert energy from sunlight into stored
Unit 2, Lesson 5: Exploring Photosynthesis
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chemical energy.
– a. Chemical energy rearranges carbon dioxide in the plant in the
presence of chlorophyll to form sugar.
– b. Glucose, a simple sugar, is formed.
Slide 3
•
C. Photosynthesis is the most important reaction on earth. All life forms are dependent on
the reaction.
– 1. Occurs in the chloroplasts
– 2. CO2 + light + chlorophyll + H2O C6H12O6 (glucose) + H2O + O2
Slide 4
•
D. In order for photosynthesis to occur, several things must be present.
– 1. Chlorophyll—green colored substance in plants.
– 2. Light—Leaves absorb necessary energy from the sun’s rays or artificial light.
– 3. Carbon Dioxide—Enters the plant through structure called stomata in the
leaves. Carbon dioxide is split during photosynthesis.
– 4. Water—Water is also split during photosynthesis.
Slide 5
• II. Photosynthesis is a series of chemical reactions that yields sugars, water, and oxygen.
– A. The chemical equation of photosynthesis can be written in words:
• Six molecules of carbon dioxide plus twelve molecules of water in
combination with a healthy plant and some form of light energy, to make
one molecule of sugar plus six molecules of water and six molecules of
oxygen.
– B. The products of photosynthesis include carbohydrates in the form of sugars
and starches as well as water and oxygen.
Give student the photosynthesis handout PSS.1.PR, PSS.2.PR, PSS.3.PR. Students will cut the
words and arrows out of this handout and paste it onto a poster board. Students can work in
groups of two. This should take ten minutes for the activity and ten minutes to go over as a class.
Now that we know the basics of photosynthesis we are going to figure out how it all happens.
You need to find a partner; if there is an odd number of you, you may need one group of three.
Each group is going to get one poster board and one set of scissors and a glue stick. I want you
to listen to all of the instructions so do not begin until I say, “Go.” Now that you have your
materials you are going to cut out all of the words and paste them on your poster board in the
order they should be. You may use your book or any other resource you have available.
Remember that this is the first three equations of five that will be on this one poster so make sure
you leave room to put the rest of them on it. There are words for different equations on each
piece of paper, so you won’t want to mix up the pieces you cut out. Is everyone ready? “Go!”
Unit 2, Lesson 5: Exploring Photosynthesis
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Once the groups are done you can pick groups to come up and explain each equation.
Have a seat but stay in your groups, I am going to pick a group now to come up and explain the
first equation. If your answers don’t match the group that is presenting, please ask questions.
This way we can ensure that everyone has the correct answers
Pick your first group.
Now for the second equation…..
Pick your second group.
Now for the third equation……
Pick your third group.
Thank you, you all did great.
Review/Summary.
Students are going to use the Karaoke Moment to describe the process of photosynthesis.
How many singers do we have in here? Great, all we need now is to divide up into groups. I will
count you off so remember your number.
Count students off into equal groups.
.
Each group is going to write a song that explains the process of photosynthesis. You only have
five minutes to write your song so you will need to be punctual. Everyone should be involved so
if any one does not feel comfortable singing I encourage your “band” to have back up singers and
if needed dancers. Is every one ready? “Go!”
“Stop!” I’m going to call up one group at a time to give us their #1 selling hit singles.
Call up groups to give their platinum selling single.
Application
Extended classroom activity:
Have students bring in labels of their favorite cereal. Compare the labels to see which
chemical substance (not an added ingredient) is the most prevalent and why? I.e.
Cornflakes have 75% starch/carbohydrates.
Unit 2, Lesson 5: Exploring Photosynthesis
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FFA activity:
Students can make an experiment limiting light on certain plants in order to make a
presentation for the class in order to qualify for the Chapter FFA Degree.
SAE activity:
Students can develop an experimental SAE using this concept in the chapter greenhouse.
Evaluation.
PSS.Assess.2
Answers to Assessment:
1. A. Carbon Dioxide
B. Water
C. Sugar/carbohydrate/glucose
D. Oxygen
E. 6H2O
F. 6 02
2. A. C6H12O6
B. 6CO2
C. Oxygen
D. Carbohydrate
Suggested Scoring:
1. A) 4 points
B) 4 points
C) 4 points
D) 4 points
E) 4 points
F) 4 points
2. A) 4 points
B) 4 points
C) 4 points
D) 4 points
Total points: 40 points
Unit 2, Lesson 5: Exploring Photosynthesis
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PSS.Assess.2
Name: ___________________
Photosynthesis and Respiration
1. Fill in the following equations for Photosynthesis:
Word equation
sunlight & chlorophyll
a.____________+b.______________
c.____________ +d._____________
Symbolic equation
sunlight & chlorophyll
6 CO2 + e._______
C6H12O6 + f.______
2. Fill in the following equations for Cellular Respiration:
Symbolic equation
a._________
+ 6O2 b._______ + 6H2O
Word equation
Glucose + c. ___________
d._________________ + Water
(Sugar or carbohydrate)
Unit 2, Lesson 5: Exploring Photosynthesis
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