All living things need to go through cellular respiration to convert sugars into energy. While this process usually involves oxygen, a type of respiration called fermentation does not (which is why it�s also called anaerobic respiration). Humans have long known about fermentation for use in bread and beverages, but have recently harnessed this for making fuel. One of the products of fermentation is ethanol, a kind of alcohol. Another is CO2, which can be measured to determine the rate of yeast fermentation. In this experiment, Saccharomyces cerevisiae will be used as a constant, but different sugar solutions will be tested. Depending on the solutes present in the solution, yeast fermentation will be more or less efficient. In this experiment,
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Stevia hasn�t been examined as a source of biofuel, but through fermentation could generate interesting pharmaceutical compounds. Intriguingly, it could even act as a cure against cancer while also being a sugar substitute. Sucrose is made up of multiple carbon rings so it might have more energy. Alternatively, since stevia glycosides have a lot of carbon rings they might also have a lot of energy too, which makes the question addressed by this study of whether stevia is fermentable an important one. I hypothesize that table sugar will ferment the most since it�s pure sucrose, that the sugar mixes (Equal and Splenda) will ferment equally because they are both mixes, but not as well as the pure sucrose, and that the stevia will ferment the least since it isn�t actually …show more content…
I will use five different solutions: 1% sucrose, 1% glucose, 1% Equal sugar substitute, 1% Splenda sugar substitute, and 1% Stevia solution. I will put 15 mL of each solution in its own test tube with a S. cerevisiae solution made of yeast and water. I will record the air bubble height and allow the test tubes to ferment for two hours in a warm place, approximately 85� C. After 2 hours I will measure the air space again and compared to the initial air space height to calculate the value of fermentation. The more air present, the more CO2 generated in fermentation.
The experimental results did not support my hypothesis. The glucose and sucrose solutions both gained 1 cm, and the Equal and Splenda solutions gained 1.7 and 0.3 cm respectively. The Stevia solution did not change. These results indicate that aspartame is actually more digestible by yeast than sucrose or glucose, while Splenda is marginally fermentable, and Stevia is not
Stevia hasn�t been examined as a source of biofuel, but through fermentation could generate interesting pharmaceutical compounds. Intriguingly, it could even act as a cure against cancer while also being a sugar substitute. Sucrose is made up of multiple carbon rings so it might have more energy. Alternatively, since stevia glycosides have a lot of carbon rings they might also have a lot of energy too, which makes the question addressed by this study of whether stevia is fermentable an important one. I hypothesize that table sugar will ferment the most since it�s pure sucrose, that the sugar mixes (Equal and Splenda) will ferment equally because they are both mixes, but not as well as the pure sucrose, and that the stevia will ferment the least since it isn�t actually …show more content…
I will use five different solutions: 1% sucrose, 1% glucose, 1% Equal sugar substitute, 1% Splenda sugar substitute, and 1% Stevia solution. I will put 15 mL of each solution in its own test tube with a S. cerevisiae solution made of yeast and water. I will record the air bubble height and allow the test tubes to ferment for two hours in a warm place, approximately 85� C. After 2 hours I will measure the air space again and compared to the initial air space height to calculate the value of fermentation. The more air present, the more CO2 generated in fermentation.
The experimental results did not support my hypothesis. The glucose and sucrose solutions both gained 1 cm, and the Equal and Splenda solutions gained 1.7 and 0.3 cm respectively. The Stevia solution did not change. These results indicate that aspartame is actually more digestible by yeast than sucrose or glucose, while Splenda is marginally fermentable, and Stevia is not