Investigative Question: How does the sugar concentration affect the fermentation of yeast?
Hypothesis:
The percentage of sugar in a solution is directly proportional to the amount of produced CO2, as a result of Yeast fermentation.
Data table:
Amount of CO2 measured in cm. (Bubble length) | Trial | Percentage of sugar in solution | | | 0% | 5% | 10% | 15% | 20% | | 1 | 0 | 0.5 | 0.5 | 0.3 | 3.1 | | 2 | 0 | 0.3 | 1.3 | 0.4 | 5 | | 3 | 0 | 0.2 | 1.5 | 1 | 2 | | 4 | 0 | 0.3 | | | | | Average | 0 | 0.33 | 1.1 | 0.57 | 3.37 |
Graph:
Conclusion:
The aim of this work was to identify how sugar concentration does affect yeast fermentation. An increase in sugar concentration must increase the release of CO2 as a result of yeast fermentation. The following analysis considers the average CO2 concentrations measured as a result of three independent experiments. In absence of sugar no CO2 was released. A 5% increase in sugar concentration showed a low CO2 presence, 0.33 cm. Then as a result of another 5% increase in sugar concentration it is observed a higher concentration of CO2, 1.1 cm measured. Till then the increase of CO2 concentration was expected. When sugar solution reached 15% surprisingly the CO2 concentration decreased to 0.57. Actually it was expected a relative increase in CO2 concentration. Later when sucrose concentration increased to 20% we identified an important increase in CO2 concentration. The whole hypothesis could not be supported as a result of the decrease in concentration when sugar concentration reached 15%.
Evaluation:
In order to improve this work we could consider the following elements: use more different samples of yeast, in this work we only had one yeast source. It could have been done more times the lab to justify and test the results. The way in which the sugar concentration was added was not accurate and changes in the temperature could have affected