GK12 Using Fermentation of Yeast to Inflate a Balloon Lesson Plan
Topic:
To observe the fermentation of yeast by measuring the volume displacement of the carbon
dioxide produced, determine which amount of sugar is optimal for yeast fermentation, and
compare which type of sugar or sugar substitute is yeast ferments best.
National Science Education Standards:
Science and Technology Standards
a. Abilities of technological design.
b. Understanding about science and technology
NSTA Standards:
5 General Skills of Teaching a- Vary their teaching actions, strategies, and methods to promote
the development of multiple students skills and levels of understanding. c- Successfully organize
and engage students in collaborative learning using different students group learning strategies.
e- Understand and build effectively upon the prior beliefs, knowledge, experiences, and interest
of students. (www.blueplanetbiomes.org)
MS Science Frameworks:
Life Science Biology I 1. Apply inquiry-based and problem-solving processes and skills to
scientific investigations.
a. Conduct a scientific investigation demonstrating safe procedures and proper care of
laboratory equipment. (Safety rules and symbols)
b. Formulate questions that can be answered through research and experimental design.
c. Apply the components of scientific processes and methods in classroom and laboratory
investigations (e.g., hypotheses, experimental design, observations, data analyses, interpretations,
theory development).
e. Analyze procedures, data, and conclusions to determine the scientific validity of
research.
f. Recognize and analyze alternative explanations for experimental results and to make
predictions based on observations and prior knowledge.
g. Communicate and defend a scientific argument in oral, written, and graphic form.
Physical Science Biology I 2. Describe the biochemical basis of life and explain how energy
flows within and between the living systems.
f. Describe the role of adenosine triphosphate (ATP) in making energy available to cells.
(DOK 1) ATP structure ATP function
g. Analyze and explain the biochemical process of photosynthesis and cellular
respiration and draw conclusions about the roles of the reactants and products in
each. (DOK 3) Photosynthesis and respiration (reactants and products) Light-dependent reactions
and light independent reactions in photosynthesis, including requirements and products of each,
Aerobic and anaerobic processes in cellular respiration, including products of each and energy
differences.
3. Investigate and evaluate the interaction between living organisms and their environment.
b. Provide examples to justify the interdependence among environmental elements.
(DOK 2) Biotic and abiotic factors in an ecosystem (e.g., water, carbon, oxygen, mold, leaves)
Objectives:
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Students will utilize lab safety techniques.
Students will use the scientific method to predict the results of the
experiment.
Students will perform current research techniques by fermenting sugar with
yeast and measuring the carbon dioxide produced.
Students will learn about alcoholic fermentation’s advantages and
disadvantages, as well as, the reactants and products involved.
Students will determine the optimum amount of sugar needed to produce the
most carbon dioxide.
Students will determine the optimum sugar or sugar substitute needed to
produce the most carbon dioxide.
Classroom Procedure:
Engage
As a classroom activity, have students stand up with their arms out straight and even with their
shoulders in a contest to see who can do it the longest. When the student’s finish this activity,
explain that they feel the burn in their muscles from lactic acid build up due to lactic acid
fermentation. Further the engage by asking the students to discuss which foods and beverages are
made from alcoholic fermentation.
Materials: willing students and a little space
Time: 15 min
Classroom arrangement: students can remain in their assigned classroom seats
Explore
Have students go to the lab and conduct and experiment to determine which amount of
granulated sugar the yeast ferments the best by measuring the carbon dioxide via volume
displacement in fifteen minute intervals over the course of an hour.
Materials:
 40°C water
 1 L beaker filled
 Permanent marker
with water
 Fleschmann’s
 String
Baker’s yeast
 Large bowl with a
 Weighing boats
pouring spout
 Balloons
 Plastic spoons
 Clothes hangar
 Scale
 Assorted graduated

Clothes
pins
cylinders
 Granulated sugar
Time: 1 hr
Classroom arrangement: students will go to the lab to their assigned lab stations with their
assigned lab group
Explain
Lecture the students on alcoholic fermentation. Discuss the pros and cons of alcoholic
fermentation to yeast. Write the chemical equations with the reactants and products on the board
and discuss its meaning.
Materials: Lab worksheet
Time: 15 min
Classroom arrangement: students can remain in their assigned classroom seats or remain in lab
with their lab groups
Elaborate
Using the predetermined amount of sugar that yeast ferments best from the first part of this lab,
have students go to the lab and conduct an experiment to determine which type of sugar or sugar
substitute the yeast ferments the best by measuring the carbon dioxide via volume displacement
in fifteen minute intervals over the course of an hour.
Materials:
 40°C water (to activate yeast)
 1 L beaker filled with water
 Fleschmann’s Baker’s yeast
 Large bowl with a pouring spout (for
volume displacement)
 Balloons
 Clothes hangar
 Scale
 Clothes pins
 Granulated sugar
 Permanent marker
 Brown sugar
 String
 D-glucose
 Weighing boats
 Sweet-N-Low
 Plastic spoons
 Equal
 Assorted graduated cylinders
 Splenda
Time: 1 hr
Classroom arrangement: students will go to the lab to their assigned lab stations with their
assigned lab group
Evaluate
Students will answer questions on the lab worksheet and have a classroom discussion comparing
results. Have the students research structures of the sugars used in the experiment, postulate how
the structures may effect alcoholic fermentation by yeast, and write a formal lab report.
Materials: Lab worksheet and Lab report
Time: 2 hrs (this lab has plenty of down time for students to be working on the lab worksheet
and lab report during experimentation)
Classroom arrangement: students will go to the lab to their assigned lab stations with their
assigned lab group
References:
1. Laird, Patricia, and Jennifer Cosgrove. “A SWELL LAB: Yeast Fermentation”
http://www.umsl.edu/~microbes/pdf/Swell%20Lab.pdf <3 April 2013>.
Name:_________________________________
Date:___________________
GK12 Using Fermentation of Yeast to Inflate a Balloon Lesson Plan
Objective:
 To record qualitative and quantitative data
 To observe the alcoholic fermentation of sugar by Baker’s yeast
 To determine the optimum amount of sugar Baker’s yeast will ferment
 To determine which types of sugar Baker’s yeast ferments best
 To determine if Baker’s yeast can ferment sugar substitutes
 To discuss the reactants and products of fermentation and how they fit into other
metabolic pathways
 To compare chemical structures of different sugars or sugar substitutes and posit how
they fit into these metabolic pathways
Introduction: (adapted from Jamie Sorrell’s A ‘Swell’ Activity)
Yeast are tiny single-celled (unicellular) fungi. The organisms in the Kingdom Fungi are
not capable of making their own food. Fungi, like any other organism, need food for energy.
They rely on sugar found in their environment to provide them with this energy so that they can
grow and reproduce.
Yeast, like bacteria grow in or on their food source. They produce and release digestive
proteins (enzymes) into their environment where the sugar molecules are found. Sugar
molecules then break down into smaller molecules that can be absorbed by the yeast and used for
food (energy).
There are many species of yeast, and each has a particular food source. Some yeast feed
on a variety of natural sources of sugar such as fruits, nectar from plants, and molasses from the
plant crop called sorghum. Others break down wood and corn stalks, during which a compound
called ethanol (like what is used in some cars) is produced. Another species breaks down sugar
from grain into alcohol. Some break down fruits into wine, which is another type of alcohol.
Bread recipes rely on yeast to break down sugar in bread dough to produce carbon dioxide gas
that causes the bread dough to rise to make a loaf.
All of these processes are called fermentation. The formula for yeast fermentation
reaction is:
For the yeast cell, this chemical reaction is necessary to produce the energy for life. The
alcohol and carbon dioxide are waste products produced by the yeast that humans utilize for
some of the processes mentioned above. The chemical reaction, known as fermentation can be
watched and measured by the amount of carbon dioxide gas that is produced from the break
down of glucose.
PART 1: WHAT AMOUNT OF SUGAR DOES YEAST FERMENT BEST?
Hypothesis:
1. Which amount of sugar will yeast ferment the best:
a) 0 g
b) 2 g c) 3 g d) 4 g e) 5 g
2. Explain your reasoning behind your answer for question
________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
3. What is the independent variable?____________________________________________
4. What is the dependent variable?_____________________________________________
Materials:








40°C water (to activate yeast)
Fleschmann’s Baker’s yeast
Balloons
Scale
Granulated sugar
Plastic spoons
Assorted graduated cylinders
Weighing boats






1 L beaker filled with water
Large bowl with a pouring spout (for
volume displacement)
Clothes hangar
Clothes pins
Permanent marker
String
Procedure:
1. Label and prepare five samples in separate balloons using different amounts of sugar as
follows:
a. 2 g yeast, 0 g sugar, and 30 ml water
b. 2 g yeast, 2 g sugar, and 30 ml water
c. 2 g yeast, 3 g sugar, and 30 ml water
d. 2 g yeast, 4 g sugar, and 30 ml water
e. 2 g yeast, 5 g sugar, and 30 ml water
2. As a negative control, no sugar or sugar substitute and only 2 g yeast and 30 ml water
will be prepared in a balloon A.
3. A weigh boat is placed on a balance and used to weigh 2 g yeast. Then a separate weigh
boat is used to measure out the specified grams of sugar for each sample. Fill each
balloon with the allotted amount of yeast and sugar.
4. Heat a beaker of approximately 200 ml water to 40°C using a hot plate.
5. Measure 30 ml of the 40°C water in a graduated cylinder and pour it into each of the
balloons.
6. Squeeze the air out of each balloon, tie it closed, and measure the initial mass and record
it in Table 1.
7. The volume of the bag is measured by the water displacement method in which the
balloon is submerged in a full 1 L beaker of water inside of a plastic tub. The excess
water that spills out of the beaker is collected from the plastic tub and placed into a
graduated cylinder where the volume can be recorded in Table 2.
8. Record the qualitative data (sight, sound, texture, smell) in Table 3.
9. Allow the balloons to hang from a clothes hanger with clothes pins for fifteen minutes,
then record the qualitative data, mass, and volume again.
10. Repeat step 9 every 15 min for 1hr.
Data:
Sample
0g
2g
3g
4g
5g
0 min
Table 1: Mass of Balloons (in grams)
15 min
30 min
45 min
60 min
Sample
0g
2g
3g
4g
5g
0 min
Table 2: Volume of Balloons (in ml)
15 min
30 min
45 min
60 min
Sample
0g
2g
3g
4g
5g
Table 3: Qualitative Data of Balloons
0 min
15 min
30 min
45 min
60 min
PART TWO: WHICH TYPE OF SUGAR OR SUGAR SUBSTITUTE DOES YEAST
FERMENT BEST?
Hypothesis:
1. What type of sugar or sugar substitute will yeast ferment best?
a) granulated sugar
2.
b) brown sugar
c) d-glucose d) Splenda e) Sweet-N-Low f) Equal
Explain the reasoning behind your hypothesis in the space provided below.
Materials:
 40°C water (to activate yeast)
 Fleschmann’s Baker’s yeast
 Balloons
 Scale
 Granulated sugar
 Brown sugar
 D-glucose
 Sweet-N-Low
 Equal
 Splenda









1 L beaker filled with water
Large bowl with a pouring spout (for
volume displacement)
Clothes hangar
Clothes pins
Permanent marker
String
Weighing boats
Plastic spoons
Assorted graduated cylinders
Procedure:
1. Label and prepare six samples in separate balloons using different amounts of sugar as
follows:
a. 2 g yeast, 0 g sugar, and 30 ml water
b. 2 g yeast, 2 g granulated sugar, and 30 ml water
c. 2 g yeast, 2 g brown sugar, and 30 ml water
d. 2 g yeast, 2 g d-glucose, and 30 ml water
e. 2 g yeast, 2 g Splenda, and 30 ml water
f. 2 g yeast, 2 g Equal, and 30 ml water
g. 2 g yeast, 2 g Sweet-N-Low, and 30 ml water
2. As a negative control, no sugar or sugar substitute and only 2 g yeast and 30 ml water
will be prepared in a balloon A.
3. A weigh boat is placed on a balance and used to weigh 2 g yeast. Then a separate weigh
boat is used to measure out the specified grams of sugar for each sample. Fill each
balloon with the allotted amount of yeast and sugar.
4. Heat a beaker of approximately 200 ml water to 40°C using a hot plate.
5. Measure 30 ml of the 40°C water in a graduated cylinder and pour it into each of the
balloons.
6. Squeeze the air out of each balloon, tie it closed, and measure the initial mass and record
it in Table 4.
7. The volume of the bag is measured by the water displacement method in which the
balloon is submerged in a full 1 L beaker of water inside of a plastic tub. The excess
water that spills out of the beaker is collected from the plastic tub and placed into a
graduated cylinder where the volume can be recorded in Table 5.
8. Allow the balloons to hang from a clothes hanger with clothes pins for fifteen minutes,
then record the qualitative data, mass, and volume again.
9. Repeat step 8 every 15 min for 1hr.
Data:
Sample
0 g Negative
Control
Granulated
sugar
Brown sugar
Splenda
Sweet-N-Low
Equal
Sample
0 g Negative
Control
Granulated
sugar
Brown sugar
Splenda
Sweet-N-Low
Equal
Table 4: Mass of Balloons (in grams)
0 min
15 min
30 min
45 min
60 min
Table 5: Mass of Balloons (in grams)
0 min
15 min
30 min
45 min
60 min