LESSON 30: Blubber in Sea Mammals
ESTIMATED TIME Setup: 10 minutes | Procedure: 10–15 minutes
• DESCRIPTION
• MATERIALS
Use vegetable shortening to demonstrate the
insulating property of blubber in sea mammals.
• OBJECTIVE
This lesson introduces the relationship between energy
and heat and demonstrates the importance of blubber
to sea mammals. Students use vegetable shortening to
explore how blubber helps insulate sea mammals from
the cold. The lesson can be expanded to address the
functions of different organic compounds, such as
carbohydrates, proteins, and lipids, in the bodies of
animals.
• CONTENT TOPICS
Scientific inquiry; energy (energy transfer, thermal
energy, insulation); chemistry in the human body
Ziploc® bags
o Large bowls or buckets
o Water
o Ice cubes
o Solid vegetable shortening
o Mini outdoor thermometers
o
Always remember to use the appropriate safety
equipment when conducting your experiment.
Refer to the Safety First section in the Resource Guide
on pages 391–393 for more detailed information about
safety in the classroom.
Jump ahead to page 381 to view the
Experimental Procedure.
NATIONAL SCIENCE EDUCATION STANDARDS SUBJECT MATTER
This lesson applies both Dimension 1: Scientific and Engineering Practices and Dimension 2: Crosscutting Concepts
from “A Framework for K–12 Science Education,” established as a guide for the updated National Science Education
Standards. In addition, this lesson covers the following Disciplinary Core Ideas from that framework:
• PS1.A: Structure and Properties of Matter
• PS3.A: Definition of Energy
• PS3.B: Conservation of Energy and Energy Transfer
• PS3.D: Energy in Chemical Processes and Everyday Life
• LSI.A: Structure and Function
• LSI.C: Organization for Matter and Energy Flow in Organisms
OBSERVATION & RESEARCH
BACKGROUND
Energy is defined as the capacity to do work or produce
heat. Energy can take many different forms, including
light, sound, electricity, chemical bonds, mechanical
motion, and thermal energy. Thermal energy is the total
energy of particles in a substance. The transfer of
thermal energy from an object at a higher temperature
to an object at a lower temperature is known as heat.
For example, when you walk outside on a cold day, heat
flows from your body into the cold air. Likewise, if you
take a hot bath or shower, heat flows from the hot water
to your body.
Mammals, including humans, have natural body systems
that help to regulate temperature. This temperature
regulation allows them to maintain constant body
temperatures so the body can function the same way
(for the most part) in different temperatures. Our bodies
(and our actions) work to regulate how much thermal
energy is generated, conserved, and exchanged with our
environment. For example, to generate thermal energy,
You Be TheLESSON
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Activity
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378
LESSON 30: Blubber in Sea Mammals
a human’s muscles may quickly contract and shake—
they shiver. To release excess heat, we sweat or simply
seek shelter from the sun. To conserve thermal energy,
we use insulators.
Heat flow can be reduced, but not eliminated, with the
use of thermal insulators. A thermal insulator is any
material that slows down the rate at which heat is
transferred from one object to another. These insulators
help you to retain your body heat and keep you warm.
Jackets, hats, gloves, and other cold-weather clothing are
all thermal insulators used to keep you warm when you
go out in cold temperatures. When you sleep at night,
you may cover yourself with a blanket, another insulator,
to keep you warm.
Other mammals do not have clothes to keep them warm.
Instead, they have other means of keeping warm, like
blubber. Blubber is a layer of fat beneath the skin of sea
mammals, such as whales and seals. Blubber serves as
a source of energy and as a thermal insulator for these
animals.
In this experiment, vegetable shortening, a solid fat made
from vegetable oils, is used to demonstrate the insulating
property of blubber. When placing your bare hand in ice
water, you will immediately notice how cold the water is
because of the rapid transfer of heat. However, the heat
flow is slower when your hand is placed inside a bag
filled with vegetable shortening and then dipped in the
cold water. The vegetable shortening serves as an
insulator, much like blubber.
FORMULAS & EQUATIONS
The layer of blubber in sea mammals lies over the animal’s
musculature but not on its appendages, such as the flippers.
Therefore, although the blubber layer is nearly continuous,
its thickness, structure, and composition can vary greatly
not only across species, but within an individual animal as
well. Blubber is made up of lipids (specifically fats),
protein, and water.
Vegetable shortening may be produced from various
vegetable oils, primarily soybean and cottonseed oils.
These oils oxidize in air over time, causing them to
become rancid (to spoil). Hydrogenation is a chemical
process of saturating the oils with hydrogen (H) to reduce
the rate at which these oils become rancid and change their
physical characteristics (make them into solids).
CONNECT TO THE YOU BE THE
CHEMIST CHALLENGE
For additional background information, please
review CEF’s Challenge study materials online at
http://www.chemed.org/ybtc/challenge/study.aspx.
• Additional information on energy and heat can be
found in the Energy section of CEF’s Passport to
Science Exploration: Chemistry Concepts in Action.
HYPOTHESIS
uWhen your hand is covered by a bag
filled with vegetable shortening and then
placed in ice water, the vegetable shortening will
act as an insulator, keeping your hand warm.
You Be The Chemist® Activity Guide | page 379
LESSON 30: Blubber in Sea Mammals
DIFFERENTIATION IN THE CLASSROOM
LOWER GRADE LEVELS/BEGINNERS
Perform the experiment as described on page 381, and
focus on the special parts and processes animals use to
grow and survive. Discuss blubber and why it is
important to sea mammals, like whales and seals.
Ask how other mammals, such as humans and dogs,
stay warm (clothing, thick fur).
Another approach may be to discuss insulators and
conductors. Use different materials to demonstrate how
insulators and conductors work.
HIGHER GRADE LEVELS/ADVANCED STUDENTS
DESCRIPTION
Use vegetable shortening to demonstrate the insulating
property of blubber in sea mammals and explore the role
of lipids in animals’ bodies.
OBJECTIVE
This lesson introduces the relationships between energy
and heat and demonstrates the importance of blubber,
a lipid, to sea mammals. Students use vegetable shortening
to explore how blubber helps insulate sea mammals from
the cold and retain their body heat.
OBSERVATION & RESEARCH
Energy is defined as the capacity to do work or produce
heat. Energy can take many different forms, including
light, sound, electricity, chemical bonds, mechanical
motion, and thermal energy. Thermal energy is the total
energy of particles in a substance. The transfer of thermal
energy from an object at a higher temperature to an object
at a lower temperature is known as heat. For example,
when you walk outside on a cold day, heat flows from your
body into the cold air. Likewise, if you take a hot bath or
shower, heat flows from the hot water to your body.
Mammals, including humans, have natural body systems
that help to regulate temperature. This temperature
regulation allows them to maintain constant body
temperatures so the body can function the same way
(for the most part) in different temperatures. Our bodies
(and our actions) work to regulate how much thermal
energy is generated, conserved, and exchanged with our
environment. To conserve thermal energy, we use
insulators.
Heat flow can be reduced, but not eliminated, by using
thermal insulators. A thermal insulator is any material
that slows down the rate at which heat is transferred
from one object to another. These insulators help you to
retain your body heat and keep you warm. Jackets, hats,
gloves, and other cold-weather clothing are all thermal
insulators used to keep you warm when you go out in
cold temperatures. In addition to clothing and shelter,
humans are also naturally insulated by hair, skin, and
layers of lipids beneath the skin. Lipids are a type of
organic compound that are insoluble in water and help
with insulation and the regulation of body functions.
Lipids are also used to store energy in the body.
Other organic compounds in the body are carbohydrates
and proteins.
Lipids are often referred to as fats, but fats are only one
type of lipid. Fats and oils are classified as triglycerides.
Triglycerides are a part of the lipid family that are made
up of a glycerol (a type of alcohol) and three fatty acids.
The layer of triglycerides beneath the skin helps to retain
heat. Likewise, sea mammals, such as whales and seals,
have a different type of specialized lipid layer beneath
the skin, called blubber.
In this experiment, vegetable shortening, a solid fat made
from vegetable oils, is used to demonstrate the insulating
property of blubber and other fat layers. When placing
your bare hand in ice water, you will immediately notice
how cold the water is because of the rapid transfer of
heat. However, the heat flow is slower when your hand is
placed inside a bag filled with vegetable shortening and
then dipped in the cold water. The vegetable shortening,
a substance composed of lipids, exhibits insulating
properties similar to blubber.
CONNECT TO THE YOU BE THE
CHEMIST CHALLENGE
For additional background information, please
review CEF’s Challenge study materials online at
http://www.chemed.org/ybtc/challenge/study.aspx.
• Additional information on energy and heat can be
found in the Energy section of CEF’s Passport to
Science Exploration: Chemistry Concepts in Action.
• Additional information on lipids can be found in
the Organic Chemistry section of CEF’s Passport to
Science Exploration: Chemistry Concepts in Action.
You Be The Chemist® Activity Guide | page 380
LESSON 30: Blubber in Sea Mammals
EXPERIMENTATION
As the students perform the experiment, challenge them to identify the independent, dependent, and controlled variables,
as well as whether there is a control setup for the experiment. (Hint: If a certain substance is added to the bag, is there a
difference in the heat felt within the bag?) Review the information in the Scientific Inquiry section on pages 14–16 to
discuss variables.
EXPERIMENTAL PROCEDURE
1. Fill a bucket with water and ice.
2. Fill a Ziploc® bag with vegetable shortening, enough
so that it will cover the students’ hands without
overflowing the bag.
3. Take another Ziploc® bag, and turn it inside out.
Place it in the first bag with the shortening, and
connect the two bags at the zip seam. The students
should be able to insert their hands without getting
shortening on them. Add more shortening if needed.
ice water. The thermometer should simply lie
in the bag and not be held in the student’s hand.
Wait one minute to ensure that the thermometer
registers the temperature of the water. No water
should seep into the bag or the data will be
invalid.
6. After recording the temperature, allow the
thermometer to sit out for a few minutes until
it is back to room temperature.
7. Repeat the process, this time using the blubber
4. First, have the students place one hand in an
empty Ziploc® bag, and then stick that hand
in the ice water.
5. Have the students insert a thermometer into the
bag and again submerge one of their hands into the
bag.
8. Use the thermometer to measure the temperature
in the blubber bag. Again, be sure that the students
do not hold the thermometer and that no water
seeps into the bag. Record the temperature.
DATA COLLECTION
Have students record data in their science notebooks or on the following activity sheet. What is the temperature in the
bag without the vegetable shortening? What is the temperature in the bag with the vegetable shortening? You can use the
table provided in the activity sheet (or a similar one of your own) for students to record their observations.
You Be The Chemist® Activity Guide | page 381
LESSON 30: Blubber in Sea Mammals
ANALYSIS & CONCLUSION
Use the questions from the activity sheet or your own
questions to discuss the experimental data. Ask students
to determine whether they should accept or reject their
hypotheses. Review the information in the Scientific
Inquiry section on pages 14–16 to discuss valid and
invalid hypotheses.
ASSESSMENT/GOALS
Upon completion of this lesson, students should be able
to …
• Apply a scientific inquiry process and perform an
experiment.
• Define energy and identify different forms of energy.
• Define and distinguish between temperature, thermal
energy, and heat.
• Explain heat flow and how insulators can be used to
reduce the flow of heat.
• Identify different types of organic compounds in the
body (see Differentiation in the Classroom).
MODIFICATIONS/EXTENSIONS
Modifications and extensions provide alternate methods
for performing the lesson or similar lessons. They also
introduce ways to expand on the content topics presented
and think beyond those topics. Use the following
examples or have a discussion to generate other ideas
as a class.
• Before the experiment, ask the students if they know
about insulators and how they work. Ask them to
give some examples of insulators. Discuss how
humans and most land mammals keep warm.
Ask them how sea mammals stay warm.
• Discuss insulators and conductors. Show students
images of different materials and ask if they are an
insulator or conductor.
• As directed in the experiment, have each student
or group record the thermometer readings on their
activity sheets. After the experiment, pool the data
and calculate the average temperature in both setups.
Discuss the results as a class to illustrate the
importance of measurement.
REAL-WORLD APPLICATIONS
Fun Fact
Fish are often referred to as
“cold-blooded,” or ectotherms,
meaning they get their heat from
the environment, unlike humans
and other mammals that
generate their own heat.
• Thermal insulators are used in many different things,
including buildings! Building insulation materials are
used during the construction or retrofit of buildings,
such as your home or school, and are used to reduce
energy transfer. When the air conditioning is turned
on inside, your home or school will stay cool
compared to the outside temperature. Likewise, when
the heat is turned on, it will remain warmer inside.
Without insulation, the temperature inside your home
or school would be about equal to the temperature
outdoors—which may not be very comfortable!
COMMUNICATION
Discuss the results as a class and review the activity sheet.
Review the information in the Scientific Inquiry section on
pages 14–16 to discuss the importance of communication
to scientific progress.
You Be The Chemist® Activity Guide | page 382
LESSON 30 ACTIVITY SHEET: Blubber in Sea Mammals
OBSERVE & RESEARCH
1. Write down the materials you see. ____________________________________________________________________
______________________________________________________________________________________________________
______________________________________________________________________________________________________
2. How might these materials be used? __________________________________________________________________
______________________________________________________________________________________________________
______________________________________________________________________________________________________
3. Define the following key terms. Then, provide an example of each by writing the example or drawing/pasting an
image of the example.
Term
Definition
Example (write or add image)
Energy
Thermal energy
Heat
Thermal insulator
Blubber
4. Consider how vegetable shortening can be used to keep your hand warm in ice water and why.
uWrite your hypothesis. ______________________________________________________________
______________________________________________________________________________________
______________________________________________________________________________________
You Be The Chemist®Activity
ActivityGuides
Guide | page 383
LESSON 30 ACTIVITY SHEET: Blubber in Sea Mammals
PERFORM YOUR EXPERIMENT
1. Fill a bucket with water and ice.
2. Get a Ziploc® bag with vegetable shortening from your teacher.
3. Take another Ziploc® bag, and turn it inside out. Place it inside the first bag with the shortening. Connect the two
bags at the zip seam. You should be able to put your hand into this new “bag” without getting shortening on you.
4. Place your hand in a separate, empty Ziploc® bag. Then, stick that hand (with the bag over it) in the ice water.
Insert a thermometer into the bag. (Do not hold the thermometer in your hand.) Wait one minute. No water should
seep into the bag. Record the temperature.
5. Let the thermometer sit out for a few minutes until it is back to room temperature.
6. Now place your other hand in the bag with the shortening. Place the thermometer inside the bag. Put your hand
(with the bag over it) in the ice water for one minute. (Again, do not hold the thermometer in your hand.) Be sure
that no water seeps into the bag. Record the temperature.
ANALYZE & CONCLUDE
1. Record your data as well as the class average in the table below.
Temperature in Regular Bag
Temperature in Blubber Bag
Your data
Class average
2. What do you feel when you place your hand in the ice water when using the bag with vegetable shortening? Explain.
______________________________________________________________________________________________________
______________________________________________________________________________________________________
3. What do you feel when you place your hand in the ice water when using the bag with no vegetable shortening?
______________________________________________________________________________________________________
______________________________________________________________________________________________________
4. How is the vegetable shortening similar to blubber?
____________________________________________________
______________________________________________________________________________________________________
5. Is your hypothesis valid? Why or why not? If not, what would be your next steps? ____________________________
______________________________________________________________________________________________________
______________________________________________________________________________________________________
You Be The Chemist® Activity Guide | page 384
LESSON 30 ACTIVITY SHEET: Blubber in Sea Mammals
EXPAND YOUR KNOWLEDGE—ADVANCED
1. Define the following key terms. Then, provide an example of each by writing the example or drawing/pasting an
image of the example.
Term
Definition
Example (write or add image)
Lipid
Triglyceride
2. Why is blubber important to sea mammals? ____________________________________________________________
______________________________________________________________________________________________________
______________________________________________________________________________________________________
3. How do humans stay warm?
________________________________________________________________________
______________________________________________________________________________________________________
______________________________________________________________________________________________________
You Be The Chemist®Activity
ActivityGuides
Guide | page 385
LESSON 30 ACTIVITY SHEET: Blubber in Sea Mammals
ANSWER KEY Below are suggested answers. Other answers may also be acceptable.
OBSERVE & RESEARCH
Vegetable shortening, outdoor thermometers, ice cubes, Ziploc® bags, large bowl ...
1. Write down the materials you see. ____________________________________________________________________
______________________________________________________________________________________________________
______________________________________________________________________________________________________
Vegetable shortening may be used in cooking. A thermometer may be used to measure the
2. How might these materials be used? __________________________________________________________________
temperature of a substance. Ice cubes may be used to reduce the temperature of a substance. Ziploc® bags may be used to hold a
______________________________________________________________________________________________________
substance. Together, these materials may be used to explore the physical properties of blubber, represented by vegetable shortening.
______________________________________________________________________________________________________
3. Define the following key terms. Then, provide an example of each by writing the example or drawing/pasting an
image of the example.
Term
Definition
Energy
The ability to do work or produce heat.
Thermal energy
The total energy of particles in a substance.
Heat
The flow or transfer of thermal energy from one
substance to another because of differences in
temperature.
Thermal insulator
Any material that slows down the rate at which heat
is transferred from one object to another.
Blubber
A thick insulating layer of fat under the skin of sea
mammals.
Example (write or add image)
4. Consider how vegetable shortening can be used to keep your hand warm in ice water and why.
When your hand is covered by a bag filled with vegetable shortening and then placed in
uWrite your hypothesis. ______________________________________________________________
ice water, the vegetable shortening will act as an insulator, keeping your hand warm.
______________________________________________________________________________________
______________________________________________________________________________________
You Be The Chemist® Activity Guide | page 386
LESSON 30 ACTIVITY SHEET: Blubber in Sea Mammals
ANSWER KEY Below are suggested answers. Other answers may also be acceptable.
PERFORM YOUR EXPERIMENT
1. Fill a bucket with water and ice.
2. Get a Ziploc® bag with vegetable shortening from your teacher.
3. Take another Ziploc® bag, and turn it inside out. Place it inside the first bag with the shortening. Connect the two
bags at the zip seam. You should be able to put your hand into this new “bag” without getting shortening on you.
4. Place your hand in a separate, empty Ziploc® bag. Then, stick that hand (with the bag over it) in the ice water.
Insert a thermometer into the bag. (Do not hold the thermometer in your hand.) Wait one minute. No water should
seep into the bag. Record the temperature.
5. Let the thermometer sit out for a few minutes until it is back to room temperature.
6. Now place your other hand in the bag with the shortening. Place the thermometer inside the bag. Put your hand
(with the bag over it) in the ice water for one minute. (Again, do not hold the thermometer in your hand.) Be sure
that no water seeps into the bag. Record the temperature.
ANALYZE & CONCLUDE
1. Record your data as well as the class average in the table below:
Temperature in Regular Bag
Temperature in Blubber Bag
Your data
Answers will vary
Answers will vary
Class average
Answers will vary
Answers will vary
2. What do you feel when you place your hand in the ice water when using the bag with vegetable shortening? Explain.
When you use the bag with the “blubber,” your hand will feel insulated from the cold. The temperature inside of the bag will be equal to room
______________________________________________________________________________________________________
temperature, while the temperature outside of the bag will be equal to the ice water.
______________________________________________________________________________________________________
3. What do you feel when you place your hand in the ice water when using the bag with no vegetable shortening?
When you use the bag with the “blubber,” your hand will be insulated from the cold! The temperature inside the bag will be about equal to
______________________________________________________________________________________________________
to the temperature of the ice water, while the temperature outside of the bag will be equal to the ice water.
______________________________________________________________________________________________________
4. How is the vegetable shortening similar to blubber?
The shortening prevents the heat inside of the bag from transferring to the
____________________________________________________
cold water. This keeps the inside warm, much like blubber. Blubber keeps sea mammals’ heat from transferring to the cold air or water.
______________________________________________________________________________________________________
5. Is your hypothesis valid? Why or why not? If not, what would be your next steps? ____________________________
Answer 1: Valid because the data support my hypothesis.
______________________________________________________________________________________________________
Answer 2: Invalid because the data do not support my hypothesis. I would reject my hypothesis and could form a new one, such as …
______________________________________________________________________________________________________
You Be The Chemist® Activity Guide | page 387
LESSON 30 ACTIVITY SHEET: Blubber in Sea Mammals
ANSWER KEY Below are suggested answers. Other answers may also be acceptable.
EXPAND YOUR KNOWLEDGE—ADVANCED
Have students complete this section if you used the advanced differentiation information, or challenge them to find the answers to these
questions at home and discuss how these terms relate to the experiment in class the next day.
1. Define the following key terms. Then, provide an example of each by writing the example or drawing/pasting an
image of the example.
Term
Definition
Lipid
A type of organic compound that is insoluble in water and
helps with insulation and the regulation of body functions;
lipids are also used to store energy in the body.
Triglyceride
A type of organic compound that is part of the lipid family
and made up of a glycerol (a type of alcohol) and three fatty
acids.
Example (write or add image)
The temperature of the sea can get extremely cold. Blubber is vital in keeping sea
2. Why is blubber important to sea mammals? ____________________________________________________________
mammals warm so that they can survive in frigid temperatures.
______________________________________________________________________________________________________
______________________________________________________________________________________________________
3. How do humans stay warm?
The human body is constantly working to maintain homeostasis. Homeostasis is the sum of the
________________________________________________________________________
processes in the body that keep everything under the same conditions. When the external temperature drops, the human body reacts by
______________________________________________________________________________________________________
producing its own energy from the food it takes in and through shivering and other movement.
______________________________________________________________________________________________________
You Be The Chemist® Activity Guide | page 388