Cellular Respiration & FermentationJulie Barrett, Sara Brandow, Vivian

Harmon

Outline

●Fermentation and Cellular Respiration - what is it?

●How are fermentation and cellular respiration different?

●Why do we care?● A story...●2 Experiments

Experiment 1: Cellular Respiration●Snail and elodea plant measured for volume and placed in water

●Elodea plant kept in the dark●Respired for 15 minutes●Amount of CO2 in solution was measured●Respiration rate per mL of organism was calculated●Elodea plant had a higher respiration rate than the snail

●Shell accounted for volume, but not respiration

Data for Measuring CO2 Production During Respiration

Organisms

Total Volumeof Organisms

(in mL)

mL of NaOHto reach

end point(in mL)

RelativeRespiration

Rate Of Organism(in mL NaOH)

RespirationRate

Per mLof Organism(mL NaOH/

mL Organism)

Beaker 1: Snail 3.5 mL 1.2 mL 0.4 mL

0.114 mL NaOH/mL snail

Beaker 2: Elodea 1.0 mL 1.0 mL 0.2 mL

0.2 mL NaOH/mL elodea

Control Beaker 0 0.8 0 0

Results of Cellular Respiration

Experiment●Beaker 1 (snail): 0.114 mL NaOH/mL organism●Beaker 2 (Elodea): 0.2 mL NaOH/mL organism●The results of our experiment indicate that the Elodea plant had a greater respiration rate per mL of organism

●However, the shell on the snail accounted for volume, but not CO2 production

Experiment 2: Fermentation

● Seven test tubes filled with six combinations of different variables● Na Pyruvate, MgSO4, and Glucose were activators. NaF was an inhibitor.● Yeast suspension present in six of seven test tubes (seventh was control with water)●Incubation●Measurement of CO2 bubble (in mm)

Tube Pyruvate MgSO4 NaF Glucose Water Add Results

(mm of CO2 produced)*

1 7.5 mL Yeast 0.50

2 2.5mL 5.0mL Yeast 1.50

3 5.0mL 2.5mL Yeast 2.00

4 0.5mL 2.5mL 4.5mL Yeast 1.25

5 5.0mL 2.5mL Yeast 0.75

6 2.5mL 2.5mL 2.5mL Yeast 1.00

7 2.5mL 2.5mL Water 0.00

* It should be noted that these numbers are approximations due to the fact that rounded test tubes were used for this experiment and there was a small air bubble present at the beginning of this experiment.

Effects of Four Chemical Variables on CO2 Production During Anaerobic Fermentation

Variable Tube # With

Variable

Tube #For

Control

Effect ofVariable

OnRespiration

Rate

Mechanism for the Effect

Yeast 2-6 1 Increased Respiration

Yeast acts as an electron acceptor and oxidizes the pyruvate from glycolysis, releasing CO2

Glucose 2-6 7 Increased Respiration

More pyruvate causes increased CO2

production

NaF 4-6 2 Decreased Respiration

Inhibits some enzymes used during glycolysis

Na Pyruvate 6 4 Increased Respiration

Pyruvate is a product of glycolysis which is reduced to ethanol by yeast, producing CO2

MgSO4 3 2 Increased Respiration

Produces Mg2+ which acts as a cofactor that activates some enzymes that are important in glycolysis.

Results of Fermentation

Experiment●Yeast, pyruvate, MgSO4, glucose - contributed to CO2 production●NaF did not contribute to CO2 production/decreased CO2 production

Amount of CO2 Produced (in mm)

Amount of CO2 produced (in mm)

Am

ount

of C

O2

prod

uced

(in

mm

)

Conclusion

● Cellular respiration, fermentation, and how they differ●Why each are important● Gary and Glenn Glucose

References

Campbell-Reece. Biology.Custom Edition. Vol. I. San Francisco: Benjamin Cummings, 2008. II vols. CornellInstitute for Biology Teachers [Internet]. Ithaca (NY): Photosynthesis and Respirationin Elodea [modified 2008 Jun 24; cited 2010 Nov 23]. Available from: http://cibt.bio.cornell.edu/labs/dl/PELO.PDF. Vodopich-Moore. BiologyLaboratory Manual. Ninth Edition. Boston:McGraw Hill Companies, Inc., 2011.