In our experiments, we tested how yeast respire when placed in different temperatures-between one and ninety nine degrees Celsius-with varying amounts of sugar-between one gram and ten grams. Our hypothesis was if the temperature of the water and the amount of sugar increases, then the amount of carbon dioxide the yeast produces will increase as well. We used three grams of yeast and one hundred milliliters for each ten minute experiment. Once everything was measured out, and the water temperature was recorded, we placed the yeast, sugar, and water in an Erlenmeyer flask. From there, we placed a stopper attached to a rubber tube in the mouth of the flask, and the other end of the tubing upside down graduated cylinder filled with water. To measure the amount of…show more content… After ten minutes of stirring occasionally, we recorded our data. We found the yeast produced the greatest amount of carbon dioxide with five grams of sugar and water at thirty degrees Celsius. We choose to reject our hypothesis because once the temperature hits about forty degrees Celsius, the yeast begin to produce less carbon dioxide. This evidence leads us to believe the water temperature plays a greater role than the amount of sugar. According to a study done by the Kluyver Laboratory of Biotechnology, the growth, consumption of sugar, and respiration of yeast “depend on the yeast species, the nature and concentration of the sugar, [and] the availability of oxygen...” This means the type of sugar and the species of yeast may also change the experiment. Different species will respond differently. However, since we used the same type of sugar and yeast species at the same time, they cannot be considered variables. There were some unintended variables in our experiment. During the ten minutes of each test, we would stir the yeast, sugar, and water. However, we did not stir the contents at the same point in time during each