Biology – FERMENTATION LAB
Tuesday October 23, 2012
Perry High School
Mr. Pomerantz_____________________________________________________________________________Page 1 of 4
Introduction: Yeasts are unicellular microorganisms of the fungi kingdom. They are facultative anaerobe, which means that
they can respire or ferment depending upon environmental conditions. In the presence of oxygen, respiration takes place
(aerobic respiration). Without oxygen present, fermentation occurs (anaerobic respiration). Both processes require sugar to
produce cellular energy. Here is the chemical reaction of fermentation, which produces ethanol and carbon dioxide as
metabolic waste products.
Equation: C6H12O6
2C2H5OH + 2CO2
Review:
1. What kingdom do yeast belong to?
2.
Define: facultative anaerobe
3.
What is the difference between aerobic and anaerobic respiration?
4.
What is another term for anaerobic respiration?
5.
What is the purpose of sugar in the fermentation process?
6.
On the equation above, write if the molecule is a solid, liquid or gas underneath it.
Purpose & Key Concepts: In this lab, students will use the respiration products of yeast to blow up balloons. This activity
will reinforce the basic principles of respiration as a fundamental metabolic process for living organisms using yeast as a
model. It will also explore how humans use this biological knowledge in everyday life. Students will also observe the effects
of sugar amounts on yeast metabolism/activity.
Materials & Safety:
• 4, 7 inch balloons
• Funnel
• 4 teaspoons (5g each, ½ of a yeast packet) active dry yeast
• 7 teaspoons (5 g each, 1 sugar packet) sugar
• Measuring spoons/spoons/balance
• Warm water
• Graduated Cylinder
• Long Piece of String
• Ruler
Reminder: There is NO eating or drinking in the lab.
Students must not attempt to inflate the balloons with their mouths, especially after it is filled with the reacting
agents.
Variables: Read the procedure below & then answer the following questions:
1.
What variable will be changed? (Independent/Manipulated Variable)
2.
What variable will be Measured/Observed? (Dependent/Responding Variable)
Biology – FERMENTATION LAB
Tuesday October 23, 2012
Perry High School
Mr. Pomerantz_____________________________________________________________________________Page 2 of 4
Procedure:
1. Use a sharpie to number four balloons 1 – 4.
2. Use the following procedure for the corresponding balloon number. TIME IS IMPORTANT!
You may want to break this up within your team members.
Balloon 1: Place a funnel into the opening of the balloon. Pour 1 teaspoon (or equivalent) of
yeast into the balloon. Add 25 ml of warm water. Note the time on your lab chart. Tie the
end of the balloon into a knot & shake your balloon contents for 10 seconds to mix it up. Use
a string to determine the circumference of your balloon. Compare this to a ruler to determine
the length in cm. Fill out the table. Retake measurements every 5 minutes for 25 minutes.
Balloon 2: Place a funnel into the opening of the balloon. Pour 1 teaspoon of yeast (or equivalent) into the balloon.
Add 1 teaspoon (or equivalent) of sugar. Add 25 ml of warm water. Note the time on your lab chart. Tie the end
of the balloon into a knot & shake your balloon contents for 10 seconds to mix it up. Use a string to determine the
circumference of your balloon. Compare this to a ruler to determine the length in cm. Fill out the table. Retake
measurements every 5 minutes for 25 minutes.
Balloon 3: Place a funnel into the opening of the balloon. Pour 1 teaspoon of yeast (or equivalent) into the balloon.
Add 2 teaspoons (or equivalent) of sugar. Add 25 ml of warm water. Note the time on your lab chart. Tie the
end of the balloon into a knot & shake your balloon contents for 10 seconds to mix it up. Use a string to determine
the circumference of your balloon. Compare this to a ruler to determine the length in cm. Fill out the table. Retake
measurements every 5 minutes for 25 minutes.
Balloon 4: Place a funnel into the opening of the balloon. Pour 1 teaspoon of yeast (or equivalent) into the balloon.
Add 4 teaspoons (or equivalent) of sugar. Add 25 ml of warm water. Note the time on your lab chart. Tie the
end of the balloon into a knot & shake your balloon contents for 10 seconds to mix it up. Use a string to determine
the circumference of your balloon. Compare this to a ruler to determine the length in cm. Fill out the table. Retake
measurements every 5 minutes for 25 minutes.
Data & Observations:
Balloon
#
Start
Time:
Initial
Circumference
Size of Balloon (cm)
Circumference Circumference Circumference
after 5 min.
after 10 min.
after 15 min.
Circumference
after 20 min.
Circumference
after 25 min.
1
2
3
4
Write any additional and qualitative observations below:
**CLEAN UP YOUR MATERIALS PER TEACHER INSTRUCTION WHEN TIME HAS CONCLUDED**
Biology – FERMENTATION LAB
Tuesday October 23, 2012
Perry High School
Mr. Pomerantz_____________________________________________________________________________Page 3 of 4
Graphing Your Data:
Make a multi-line, color-coded graph of the data from your table below.
1. Title your graph.
2. Label your axes.
3. Create a key.
4. Plot your points.
5. Connect them with the proper color.
Why are we using a line graph?
TITLE: _____________________________________________________________ Key:
Biology – FERMENTATION LAB
Tuesday October 23, 2012
Perry High School
Mr. Pomerantz_____________________________________________________________________________Page 4 of 4
Data Calculations: (round all answers to 2 decimal places)
1.
Use the circumference of the balloon after 25 minutes (bolded in data table) and the following equations to
calculate the diameter of the balloon. Fill out the corresponding data table.
C = 2πr d = 2r
2.
Calculate the volume of gas produced using the following equation & fill out the data table.
Volume of Gas Produced = 4.187 x (diameter of balloon in cm/2)3
Balloon #
Sugar Quantity
Volume of Carbon Dioxide Gas Produced
Circumference (cm)
Diameter of Balloon
of Balloon after 25 min
(cm)
Volume of Gas Produced
(cm3)
1
2
3
4
Discussion:
1. What process was observed in this lab?
2.
What gas was produced in this process?
3.
What observation was seen to show this production of gas?
4.
Which balloon had no observable gas production? Why?
5.
Which balloon produced the largest volume of gas? How do you know? Why?
Claim & Evidence:
Based on an interpretation of your data, what can be claimed about the effects of sugar quantity on yeast fermentation? Use
evidence to support your claim.
Reflection:
1. How does this lab relate to your textbook? (provide a page number)
2.
How does this lab relate to our lecture, in class discussion or activities? (provide page # if can)
3.
How does this lab relate to the real world?