Effect Of Sucrose Concentration On Yeast Fermentation Of Yeast

Background

Fermentation is what organisms such as yeast use to breakdown sugar. This is an anaerobic process meaning that it undergoes this reaction not in the presence of oxygen. Yeast fermentation is essential to the food and beverage industry because of its products which are CO2 and ethanol. The fermentation of yeast may vary with given amounts of substrate, sugar, and enzyme, the yeast. To determine how the concentration of substrate affects the process, we will alter the amount of sucrose in each reaction.

Hypothesis

If the sucrose concentration increases in a fixed amount of yeast, then the CO2 production will proportionally increase over time.

Null Hypothesis

If the sucrose concentration increases in a fixed amount of yeast, then the CO2 production will not proportionally increase over time.

Protocol

First, we measured out 1, 3, and 5 grams of sucrose into a weigh boat and added each sample to 100 mL of distilled water. This gave us a 1%, 3%, and 5% sucrose solution. Then we activated the yeast by stirring 1 packet (7 grams) of yeast into 250mL of warm water. Then we place 11 mL of each sucrose solution into separate fermentation vials and filled the rest with the yeast solution. To have a control, we put 11mL of distilled water with the yeast in a fourth vial. After this, we place the top on each vial, created a seal and

In addition, a significant amount of liquid leaked out of the 3% and 5% vials. Each vial had an initial air bubble, so that had to be measured and accounted for. As time progressed, there became a wider gap between the 3% and 5% and the 1% and control solutions. As the reaction was taking place, it was evident CO2 was being produced due to the presence of air bubbles. The rate of reaction for 1% was 84.8 mm3/minute, for 3% it was 229.9 mm3/minute, for 5% it was 186.6 mm3/minute, and for the control it was