Fermentation Experiment

Purpose:  The purpose of this investigation is to demonstrate the process by which some cells burn a fuel without oxygen, a process called anaerobic cell respiration.  The particular type of anaerobic respiration observed in this experiment is alcohol fermentation.

Materials and Methods:  Materials required for this experiment include yeast cells, brown sugar, a 150 ml beaker, stirring rod, and a fermentation tube.

Mix brown sugar, yeast, into water in the 150 ml beaker.  Stir the mixture for several minutes. 

Experiment:  Pour the mixture into a fermentation tube.  Tilt the tube so that the mixture moves into the blind end of the apparatus.  Initially a vacuum will hold the mixture up in the blind end of the tube.  Eventually the yeast cells will burn the sugar and  produce a gas which pushes the mixture back into the bulb of the fermentation tube.

Your experiment should resemble the model shown below:

Conclusion:  Distinguish between aerobic and anaerobic respiration.

What is the gas that collects in the blind end of the fermentation tube?

What is alcohol fermentation?

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