Yeast Lab

by Liz LaRosa

www.middleschoolscience.com

Click here for Teacher Notes
 

Objectives:

Procedure:

  1. Label your flask with your assigned group letter: A, B, C, D, or E.

  2. For each Flask:

  3. Fill the flask with 100mL of warm water

  4. Place balloon over top of flask and rubber stopper (with one hole) tightly

  5. Swirl flask to mix contents

  6. Record observations in Table 1.

  7. (Due to 45 min class, flasks were left overnight)

  8. Measure the height of the balloon from the top of the stopper to the top of the balloon and record in Table 1.

Data:  

Table 1 : Observations and Measurements of Balloon height in cm  

Flask

Observations

Period 1

Period 2

Period 3

Period 5

Period 6

Average

A

 

 

 

 

 

 

 

B

 

 

 

 

 

 

 

C

 

 

 

 

 

 

 

D

 

 

 

 

 

 

 

E

 

 

 

 

 

 

 

Figure 1: Graph of Balloon Height in cm

Analysis:

  1. Compare what happened to each of the balloons for flasks A through E.

  2. Why did we use warm water instead of cold water?

  3. What flask(s) had the Most CO2 production? Least? How do you know? Be sure to describe WHY!

  4. Describe what happened using the following terms : yeast, warm water, sugar, salt, and carbon dioxide.

  5. Was there anything besides CO2 produced in the flask? What was it?

Conclusion:

2-3 sentences on what you learned in lab

Please note: this lab has been modified from its original source: "Exploring Life Science" by Prentice Hall.