The Effect of Sugar on the Amount of Carbon Dioxide

Produced by Yeast

Kathleen Fuh12/22/10

Mrs. Pietrangelo

Problem Statement

• What effect does sugar have on the amount of carbon dioxide produced by yeast?

Background

• Yeast– Eukaryotic– Kingdom Fungi– Uses sugar– Fermentation/Cellular Respiration– ANOVA

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.

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 5 5 5 5

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

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

Procedure

1. Gather all materials

2. Measure yeast

3. Make sugar solutions

4. Mix yeast and solutions

5. Wait three hours

6. Measure volume – by displacement

7. Repeat

Photos

Results

Levels Trial 1 Trial 2 Trial 3 Trial 4 Trial 5 Avg.*

0% 20 30 50 30 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

* Numbers in mL

GraphThe Effect of Sugar on the Amount of Carbon

Dioxide Produced by Yeast

0

200

400

600

800

1000

1200

0 5 10 15 20

Concentration of Solution (%)

Vo

lum

e o

f C

O2

(mL

)

Avg. Volume

ANOVA

 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

Results

• P value indicates…(relate back to null)

• Graph shows…

Conclusion

• Hypothesis supported

• Null rejected

• As sugar concentration increases amount of carbon dioxide produced increases

• Application: baking bread

Sources of Error/Improvements

• Air in balloons

• Creating solutions

• Measuring volume

• Make air-tight

• Use different beakers

• Set amount of water used

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)?

Acknowledgements

• Parents

• Mrs. Pietrangelo

BibliographyAshe, Arthur J., III. “Yeast.” World Book Student. World Book,

2010. Web. 6 Oct. 2010.

Campbell, Neil A., Jane B. Reece, Lawrence G. Mitchell, and Martha R. Taylor. Biology: Concepts & Connections. 4th ed. San Francisco: Benjamin Cummings, 2003. Print.

Rose, Emily Jane. “Carbon Dioxide.: World Book Student. World Book, 2010. Web. 6 Oct. 2010.

“The Yeast. (Saccharomyces cerevisiae and Schizosaccharomyces pombe).” The Scientist. 2 June 2003: S12+. Gale Science in Context. Web. 5 Oct. 2010.

“Yeast.” U*X*L Encyclopedia of Science. U*X*L, 2007. Gale Science in Context. Web. 5 Oct. 2010.