Lesson 4 | Cells and Energy
Student Labs and Activities
Page
66
Content Vocabulary
67
Lesson Outline
68
Content Practice A
70
Content Practice B
71
School to Home
72
Key Concept Builders
73
Enrichment
77
Challenge
78
Lab A
81
Lab B
84
Lab C
87
Chapter Key Concepts Builder
88
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
Launch Lab
Cell Structure and Function
65
Name
Date
Launch Lab
Class
LESSON 4: 5 minutes
What do you exhale?
Does the air you breathe in differ from the air you breathe out?
Procedure
1. Read and complete a lab safety form.
3. In your Science Journal, record any
2. Unwrap a straw. Use the straw to
changes in the solution.
slowly blow into a small cup of
bromthymol blue. Do not splash the
liquid out of the cup.
Think About This
1. What changes did you observe in the solution?
2. What do you think caused the changes in the solution?
Key Concept Why do you think the air you inhale differ from the air you
exhale?
66
Cell Structure and Function
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
3.
Name
Date
Class
Content Vocabulary
LESSON 4
Cells and Energy
Directions: In this word search puzzle, find and circle the four terms listed below. Then write each term on the
line before its definition.
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
cellular respiration
fermentation
glycolysis
photosynthesis
F
H
G
L
X
R
L
X
P
O
B
J
K
A
L
F
C
M
X
E
R
R
S
P
A
Y
I
K
M
U
Y
G
I
Q
Y
B
P
Q
R
C
Y
F
K
Q
N
I
Y
S
N
S
V
F
V
Y
D
H
N
M
A
R
W
W
G
K
U
B
E
J
S
W
C
R
A
O
O
L
E
G
Y
U
L
I
C
W
W
T
J
T
E
Z
J
S
O
T
C
N
V
L
X
F
D
B
W
Q
Y
S
B
Z
K
V
E
J
O
L
T
E
E
Y
C
X
H
V
S
B
V
H
E
K
X
Z
O
S
F
A
J
F
X
C
W
U
D
N
I
N
Z
P
Z
O
E
C
Y
I
T
D
H
U
W
O
A
V
A
G
C
H
F
P
V
A
J
N
E
I
N
A
F
M
I
L
Z
K
Z
F
F
B
A
H
U
F
T
G
O
Q
G
O
R
B
S
Y
P
A
V
F
B
B
K
N
I
H
C
N
O
I
T
A
R
I
P
S
E
R
R
A
L
U
L
L
E
C
K
Q
O
E
P
G
K
V
G
I
Y
S
O
L
U
S
I
S
B
V
Z
A
Y
U
P
P
E
Q
B
S
J
I
E
V
B
T
I
O
U
Q
E
S
H
W
E
U
D
K
Y
R
G
W
N
G
M
S
Y
1. Cells use oxygen in this process to convert food energy
into ATP.
2. This is a reaction used by cells to obtain energy from food
when oxygen levels are low.
3. This process breaks apart glucose.
4. This process converts light energy into glucose and
releases oxygen.
Cell Structure and Function
67
Name
Date
Class
Lesson Outline
LESSON 4
Cells and Energy
A. Cellular Respiration
1. All
2.
things need energy to survive.
is a series of chemical reactions that convert the energy
in food molecules into a usable form of energy called ATP.
3. The first step of cellular respiration, called glycolysis, occurs in the
of all cells.
4. During glycolysis
, a sugar, is broken into smaller
molecules.
5. The second step of cellular respiration occurs in the
of
eukaryotic cells. This step requires
.
6. During the second step of cellular respiration, the smaller molecules made during
are broken down. Large amounts of usable energy,
called
7.
, are produced.
and carbon dioxide (CO2) are two waste products that
are given off during the second step of cellular respiration.
1. Eukaryotic and prokaryotic cells use fermentation to obtain energy from food when
levels are low.
2. Fermentation occurs in a cell’s
.
3. Lactic-acid fermentation converts
into ATP and a waste
product called lactic acid.
4. Some types of bacteria and yeasts make ATP during
fermentation. This process produces
and CO2.
C. Photosynthesis
1. Plants and some unicellular organisms obtain energy
from
.
2. Photosynthesis is a series of chemical reactions that convert light energy, water, and
CO2 into
3. In plants, light energy is absorbed by
and
.
such as
chlorophyll.
68
Cell Structure and Function
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
B. Fermentation
Name
Date
Class
Lesson Outline continued
4. The chemical reactions of photosynthesis occur in
, the
organelles in plant cells that convert light energy into food.
5. Photosynthesis uses CO2 that is released during
to
make food energy and release oxygen.
6. When an organism eats plant material, it takes in
released during
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
energy. An organism’s cells use
photosynthesis.
Cell Structure and Function
69
Name
Date
Class
Content Practice A
LESSON 4
Cells and Energy
Directions: Put the following steps in the correct order from 1 to 7. Then add the information to the flowchart to
show the steps in cellular respiration.
Chemical reactions occur in the cell’s cytoplasm.
Small molecules enter mitochondria.
Carbon dioxide is released from the cell.
Water is released from the cell.
Small amounts of ATP are released.
Sugar molecules enter a cell.
Large amounts of ATP are produced.
1.
2.
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
7.
3.
6.
4.
5.
70
Cell Structure and Function
Name
Date
Class
Content Practice B
LESSON 4
Cells and Energy
Directions: Work with a partner. Take turns quizzing each other by reading the questions aloud. Use the
textbook to research answers that you are unsure about.
1. What does cellular respiration convert?
2. In which organelle does respiration take place?
3. What happens during glycolysis?
4. What three things are produced during the second step of respiration?
5. How does the process of fermentation differ from the process of respiration?
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
6. Where can the process of lactic-acid fermentation be found?
7. What do human and animal cells obtain through lactic-acid fermentation during
exercise?
8. What does alcohol fermentation produce?
9. What do plant cells use to produce glucose and oxygen?
10. What is reflected by a plant to give it a green color?
11. What does an animal take in when it eats a plant?
12. Which molecules are involved in photosynthesis and respiration?
Cell Structure and Function
71
Name
Date
School to Home
Class
LESSON 4
Cells and Energy
Directions: Use your textbook to answer each question or respond to each statement.
1. What is cellular respiration?
2. In which two parts of the cell does cellular respiration occur?
3. How is fermentation similar to cellular respiration?
4. How is fermentation different from cellular respiration?
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
5. What is photosynthesis?
6. Identify the following chemical reactions:
a. 6CO2 + 6H2O → C6H12O6 + 6O2
b. C6H12O6 → ATP (energy) + lactic acid
c. C6H12O6 → 6O2 + 6H2O + ATP (energy)
d. C6H12O6 → ATP (energy) + CO2 + alcohol
72
Cell Structure and Function
Name
Date
Class
Key Concept Builder
LESSON 4
Cells and Energy
Key Concept How does a cell obtain energy?
Directions: Label this diagram by writing the correct term from the word bank on each line. Some terms may be
used more than once.
carbon dioxide
light energy
oxygen
reactions in chloroplasts
reactions in cytoplasm
reactions in mitochondria
water
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
Cellular Respiration in Plant and Animal Cells
1. _______________
2. _______________
_______________
_______________
Glucose is broken down
into smaller molecules.
Smaller molecules are
processed releasing
energy.
3. ______________
______________
4. ______________
______________
Photosynthesis in Plant Cells
5. ______________
______________
6. ______________
______________
Cell Structure and Function
7. _______________
_______________
8. ______________
Light, energy, water, and
carbon dioxide react to
produce glucose (stored
energy).
______________
73
Name
Date
Key Concept Builder
Class
LESSON 4
Cells and Energy
Key Concept How does a cell obtain energy?
Directions: Complete the chart to explain the process of cellular respiration.
Create a diagram showing where glycolysis
occurs.
Step 2 Explain the production of ATP in
mitochondria and identify which molecule is
required for the process.
Create a diagram of a mitochondrion showing
what occurs in Step 2.
Alternate Step—Fermentation Explain what
fermentation is and compare the type of
fermentation used by humans to obtain energy
with the type used by some kinds of bacteria.
Create a diagram comparing the two types of
fermentation.
74
Cell Structure and Function
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
Step 1 Explain the process of glycolysis and tell
where it occurs.
Name
Date
Class
Key Concept Builder
LESSON 4
Cells and Energy
Key Concept How do some cells make food molecules?
Directions: On each line write the correct term from the word bank.
carbon dioxide
glucose
light energy
oxygen
water
Sun
1.
Chloroplast
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
2.
and 3.
Mitochondrion
4.
ATP (energy)
and 5.
Directions: Circle the term in parentheses that correctly completes each sentence.
6. In photosynthesis, light energy is absorbed by (water/chlorophyll) and
other pigments.
7. The chemical reactions of photosynthesis occur in organelles called
(chloroplasts/mitochondrion).
8. In photosynthesis, light energy, water, and (carbon dioxide/oxygen) are used
to make sugars.
9. Photosynthesis also produces (oxygen/carbon dioxide) that is released into
the atmosphere.
Cell Structure and Function
75
Name
Date
Class
Key Concept Builder
LESSON 4
Cells and Energy
Key Concept How does a cell obtain energy?
Directions: Use the diagram to complete the chart below. Write five questions for cellular respiration and five
questions for photosynthesis. Then trade with a partner and answer your partner’s questions.
Photosynthesis
Light
Energy
Carbon
Dioxide
Oxygen
Sugar
Water
Vapor
Respiration
Energy
Released
Question
Example: What is needed for respiration?
Answer
Sugar and oxygen are needed for respiration.
1.
2.
3.
4.
5.
76
Cell Structure and Function
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
Photosynthesis and Cellular Respiration
Name
Date
Class
Enrichment
LESSON 4
Photosynthesis Takes on World Hunger
Hunger affects millions of people
worldwide. Scientists are working hard
to find solutions to this problem. A promising
solution might be found in one of the most
common processes on Earth—photosynthesis.
During photosynthesis, plants and
certain algae use sunlight, carbon dioxide,
and water to make sugar-rich food.
Photosynthesis releases oxygen into the
atmosphere; the oxygen is used by living
things during cellular respiration.
Photosynthesis is clearly crucial to life
functions. However, it is not an efficient
process. At best, plants store only about 1
percent of the energy they receive from the
Sun. By improving the efficiency of
photosynthesis, scientists hope to increase
crop yields.
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
Switching Enzymes
Enzymes are proteins that break larger
molecules into smaller molecules. The
rubisco enzyme is the most abundant
protein on Earth. In photosynthesizing
organisms, the rubisco enzyme helps take
in carbon dioxide and convert it into
sugars and other compounds. It is also slow
and inefficient.
Red algae, however, contain a more
efficient form of rubisco. Scientists theorize
that they can increase crop yields by
replacing the enzyme currently found in
grains and other crops with the more efficient
form of rubisco. Or they might be able to
alter the rubisco in crops so it resembles the
more efficient form of the enzyme.
Mixed Reviews
Scientists are divided about whether
these theories hold true promise. Some
scientists state that studies thus far have not
proved the connection between increasing
the efficiency of photosynthesis and
increasing crop yields. Other scientists insist
that making photosynthesis more efficient
leads to marked increases in crop yields—as
much as 12 percent in a two-year period.
As the debate over rubisco continues,
scientists are exploring other methods of
improving the efficiency of photosynthesis.
For example, photosynthetic efficiency
might be increased by forcing large
amounts of carbon dioxide into a plant’s
cells, a process know as supercharging.
Using these and other techniques, scientists
hope to substantially reduce world hunger.
Applying Critical-Thinking Skills
Directions: Answer each question.
1. Apply Assume that scientists are successful in putting the more efficient form of
rubisco into common crops. Could you assume that such crops would produce higher
yields when they are grown in fields? Why or why not?
2. Judge Some scientists do not see any promise in increasing the efficiency of
photosynthesis, but other scientists do. How could you decide which argument to support?
3. Weigh What possible disadvantages might be associated with increasing the efficiency
of photosynthesis?
Cell Structure and Function
77
Name
Date
Class
Challenge
LESSON 4
Cellular Respiration and Photosynthesis
Directions: Complete the table to compare cellular respiration and photosynthesis. Use the information in the
completed table to write a poem that compares cellular respiration and photosynthesis.
Comparison of Cellular Respiration and Photosynthesis
Cellular Respiration
Photosynthesis
1.
2.
Reactants
3.
4.
Products
5.
6.
Chemical Equation
7.
8.
78
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
Where It Occurs
Cell Structure and Function
Name
Date
Class
Lab A
50 minutes
Photosynthesis and Light
You might think of photosynthesis as a process of give and take. Plant cells take in water
and carbon dioxide and, powered by light energy, make their own food. Plants give off
oxygen as a waste product during photosynthesis. Can you determine how the intensity of
light affects the rate of photosynthesis?
Ask a Question
How does the intensity of light affect photosynthesis?
Materials
test tube
lamp
Elodea
watch or clock
scissors
thermometer
beaker
Safety
Make Observations
1. Read and complete a lab safety form.
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
2. Cut the bottom end of an Elodea stem at an angle and lightly crush the cut end.
Place the Elodea in a test tube with the cut side at the top. Fill the test tube with
water.
Stand the test tube and a thermometer in a beaker filled with water. (The water in
the beaker keeps the water in the test tube from getting too warm under the lamp.)
3. Place the beaker containing your test tube on a circle drawn on a sheet of paper
under a lamp.
Measure and record the temperature of the water in the beaker.
4. When bubbles of oxygen begin to rise from the plant, start counting the number of
bubbles per minute.
Record your data in the Control column of the data table on the next page.
Continue to record data for 10 minutes.
5. Record the temperature of the water in the beaker at the end of the test.
Cell Structure and Function
81
Name
Date
Class
Lab A continued
6. Calculate the average number of bubbles produced per minute by your plant.
Sample Data Table
Number of Bubbles per Minute
Time
Control
Dimmer Light
1
2
3
4
5
6
7
8
9
10
Form a Hypothesis
8. Use your data to form a hypothesis relating the amount of light to the rate of
photosynthesis.
Test Your Hypothesis
9. Repeat the experiment, changing the light variable so that you are observing your
plant’s reaction to getting more or less light. Keep all other conditions the same.
10. Record your data in the Dimmer Light column of the data table.
Calculate the average number of bubbles per minute.
82
Cell Structure and Function
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
7. Compare your data with your classmates’ data.
Name
Date
Class
Lab A continued
Lab Tips
To calculate the average number of bubbles per minute,
add the total number of bubbles observed in 10 minutes,
and then divide by 10.
Analyze and Conclude
11. Use Variables How does the intensity of light affect
photosynthesis? What is your evidence?
Remember to use scientific
methods.
Make Observations
Ask a Question
Form a Hypothesis
Test your Hypothesis
Analyze and Conclude
Communicate Results
12.
The Big Idea How do plant cells make food?
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
What do they take in and what do they give off? What
source of energy do they use?
Communicate Your Results
Compile all the class data on one graph to show the effects of varying amounts of light on
the rate of photosynthesis.
Cell Structure and Function
83
Name
Date
Class
Lab B
50 minutes
Photosynthesis and Light
You might think of photosynthesis as a process of give and take. Plant cells take in water
and carbon dioxide and, powered by light energy, make their own food. Plants give off
oxygen as a waste product during photosynthesis. Can you determine how the intensity
of light affects the rate of photosynthesis?
Ask a Question
How does the intensity of light affect photosynthesis?
Materials
test tube
lamp
Elodea
watch or clock
scissors
thermometer
beaker
Safety
Make Observations
1. Read and complete a lab safety form.
2. Cut the bottom end of an Elodea stem at an angle and lightly crush the cut end. Place
3. Place the beaker containing your test tube on a circle drawn on a sheet of paper under a
lamp. Measure the temperature of the water in the beaker. Record the temperature.
4. When bubbles of oxygen begin to rise from the plant, start counting the number of
bubbles per minute. Continue to record data for 10 minutes.
5. Record the temperature of the water in the beaker at the end of the test.
6. Calculate the average number of bubbles produced per minute by your plant.
7. Compare your data with your classmates’ data.
84
Cell Structure and Function
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
the Elodea in a test tube with the cut side at the top. Fill the test tube with water. Stand
the test tube and a thermometer in a beaker filled with water. (The water in the beaker
keeps the water in the test tube from getting too warm under the lamp.)
Name
Date
Class
Lab B continued
Sample Data Table
Number of Bubbles per Minute
Time
Control
Dimmer Light
1
2
3
4
5
6
7
8
9
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
10
Form a Hypothesis
8. Use your data to form a hypothesis relating the amount of light to the rate of
photosynthesis.
Test Your Hypothesis
9. Repeat the experiment, changing the light variable so that you are observing your
plant’s reaction to getting more or less light. Keep all other conditions the same.
10. Record your data in the data table, and calculate the average number of bubbles per
minute.
Cell Structure and Function
85
Name
Date
Class
Lab B continued
Lab Tips
To calculate the average number of bubbles per minute,
add the total number of bubbles observed in 10 minutes,
and then divide by 10.
Analyze and Conclude
11. Use Variables How does the intensity of light affect
photosynthesis? What is your evidence?
Remember to use scientific
methods.
Make Observations
Ask a Question
Form a Hypothesis
Test your Hypothesis
Analyze and Conclude
Communicate Results
12.
The Big Idea How do plant cells make food?
What do they take in and what do they give off?
What source of energy do they use?
Compile all the class data on one graph to show the
effects of varying amounts of light on the rate of
photosynthesis.
Extension
What other variables might affect the rate of photosynthesis? For example, how does
different-colored light or a change in temperature affect the rate of photosynthesis?
To investigate your question, design a controlled experiment.
86
Cell Structure and Function
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
Communicate Your Results
Name
Date
Class
Lab C
Temperature and the Rate of Photosynthesis
Directions: Use the information and data from the Lab Photosynthesis and Light to perform this lab.
You have learned that the intensity of light affects the rate of photosynthesis. Other factors
such as different colors of light or different temperatures can also affect the rate of
photosynthesis. Design an experiment to determine how different temperatures affect the
rate of photosynthesis.
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
Please note that you must complete Lab B before beginning Lab C. Also, have your teacher
approve your design and safety procedures before beginning your experiment.
Cell Structure and Function
87
Name
Date
Class
Chapter Key Concepts Builder
Cell Structure and Function
End-of-Chapter Practice
Directions: Work with a group to create a poster showing the structures and functions of a cell. Here are the
steps you will need to take to complete this activity:
• As a group, form two subgroups. One subgroup will study prokaryotic cells. The other
subgroup will study eukaryotic cells.
Who Will Study Prokaryotic Cells:
Who Will Study Eukaryotic Cells:
• Then, complete the chart below.
Make a list of cell structures for
your cell type.
Note the function of each cell
structure for your cell type.
Note how cellular material is
moved in and out of cells.
• As a group, think of ways to illustrate the information you have.
Ideas for illustrating our information:
• As a group, decide on the best way to illustrate your information on cell structure
and function.
• Work together to complete your illustration plans.
• Present your work to your class. Allow time for questions and answers.
88
Cell Structure and Function
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
• Next, share your information with your group.