1. The Effect of Sugar on the Amount of Carbon Dioxide Produced by Yeast
Kathleen Fuh
12/22/10
Mrs. Pietrangelo

2. Problem Statement
What effect does sugar have on the amount of carbon dioxide produced by yeast?

3. Background Yeast Eukaryotic Kingdom Fungi Uses sugar
Fermentation/Cellular Respiration
ANOVA
Eukaryotic – membrane bound organelles
Mention – type in the scientific name of yeast

4. Hypothesis
If the concentration of sugar is increased then the amount of carbon dioxide produced by yeast will increase.
Null: Sugar does not affect the amount of carbon dioxide produced by yeast.

5. Design Diagram
Title: The effect of sugar concentration on the amount of carbon dioxide produced by yeast
Hypothesis: If the concentration of sugar is increased then the amount of carbon dioxide produced by yeast will increase.
IV: concentration of sugar (% by mass)
Levels
0% (control) 5%
10%
15%
20%
Trials 5

6. Design Diagram (cont’d)
DV: Amount of carbon dioxide produced (mL)
Control: no sugar added (0% solution)
Constants: amount of yeast, bottle, volume of solution, balloons

7. Materials 25 balloons 5 glass bottles Water Granulated sugar
Active dry yeast
2 graduated cylinders (mL)
2 buckets (one bigger than the other)
Triple beam balance
Small plastic container
Plastic lid
Funnel

8. Procedure Gather all materials Measure yeast Make sugar solutions
Mix yeast and solutions
Wait three hours
Measure volume – by displacement
Repeat

9. Photos

10. Results Levels Trial 1 Trial 2 Trial 3 Trial 4 Trial 5 Avg.* 0% 20 30
* Numbers in mL
Levels
Trial 1
Trial 2
Trial 3
Trial 4
Trial 5
Avg.* 0% 20 30 50 35 33 5%
620
760
850
645
780
731
10%
820
810
885
800
870
837
15%
1070
1005
905
985
920
977
20%
1100
1090
950
1000
1200
1068

11. Graph

12. ANOVA Sum of Squares df Mean Square Fisher F-Value Sig. Between Groups
Sum of Squares df
Mean Square
Fisher F-Value
Sig.
Between Groups
3,362,544 4
840,636
170
0.000
Within Groups
98,716 20
4,935
Total
3,461,260 24
P value =
*Cite online calculator here

13. Results
P value indicates…(relate back to null)
Graph shows…

14. Conclusion Hypothesis supported Null rejected
As sugar concentration increases amount of carbon dioxide produced increases
Application: baking bread

15. Sources of Error/Improvements
Air in balloons
Creating solutions
Measuring volume
Make air-tight
Use different beakers
Set amount of water used

16. Extensions How other variants affect yeast
Temperature, pH
Does it ever reach a certain point where the yeast can no longer produce more CO2 (not dependent on sugar)?

17. Acknowledgements
Parents
Mrs. Pietrangelo

18. Bibliography
Ashe, Arthur J., III. “Yeast.” World Book Student. World Book, Web. 6 Oct
Campbell, Neil A., Jane B. Reece, Lawrence G. Mitchell, and Martha R. Taylor. Biology: Concepts & Connections. 4th ed. San Francisco: Benjamin Cummings, Print.
Rose, Emily Jane. “Carbon Dioxide.: World Book Student. World Book, Web. 6 Oct
“The Yeast. (Saccharomyces cerevisiae and Schizosaccharomyces pombe).” The Scientist. 2 June 2003: S12+. Gale Science in Context. Web. 5 Oct
“Yeast.” U*X*L Encyclopedia of Science. U*X*L, Gale Science in Context. Web. 5 Oct