Cellular respiration and fermentation Lab Report

Cellular respiration and fermentation - Lab Report Example The researcher states that studying fermentation and respiration as done in this experiment has implications for industry, as fermentation reactions, for one, impact the way we produce an important industrial product for instance, in this case, ethanol. The nature of the sugar matters too, as the use of particular kinds of sugars in ethanol production, to use the same example, affect a number of products that are produced in such reactions. In the first part, fermentation is measured using gas height as the proxy for carbon dioxide measure and the rate of reaction. In the second part, respiration is measured in terms of carbonic acid production. Â  The key materials used are the following: 10 percent sucrose solution; 10 percent glucose solution; peas; distilled water; phenol red; yeast stock; wax pencil; water bath; hot plate; test tubes of various sizes; beaker; test tube corks and holders; test tube rack. The idea behind the test tubes of varying sizes is to create a respirometer using two sizes of test tubes, for the experiment involving the yeasts. A practice session involves filling the smaller tube, measuring 15 x 125 mm with water, placing that inside a 20x150 mm test tube, and inverting to the point where the air bubble in the smaller test tube is as small as can be made from the process. In the actual experiment, three different test tubes are filled with two-thirds of either ten percent sucrose solution, ten percent glucose solution, or distilled water, and then topped off to the brim with yeast suspension. The inversion method practiced above is utilized to mix the solutions and form the respirometers. The respirometers are allowed to incubate for one hour, while placed in a water bath set at 37 degrees Celsius. The gas bubble heights are measured after the period of incubation. The idea is to be able to undertake a comparison of how the three sources of food in the test tube compare with regard to their suitability as food for yeast. This is the f irst part of the experiment (Experiment 7 n.d., pp. 59-61). In part two of the experiment, 10 peas that were either soaked, not soaked, and soaked and boiled were placed in each of three different test tubes, filled with water up to the two-thirds level, and covered with corks. After an hour and a half, two drops of phenol red were placed in each of the three test tubes containing the seeds, more when no color was visible or the color is too vague/thin. The results of the color observations were tabulated. (Experiment 7 n.d., pp. 59-61) Results The first part of the experiment measured the amount of respiration from the fermentation process, involving the yeast solution and the three food sources. Among the three food sources, the glucose solution had the highest change in the gas height at the end of the incubation period, with the gas height changing from the initial 1 mm to 6 mm. The sucrose solution had a lower gas height change, going from 1 mm initially to 4 mm at the end of the observation period. The test tube containing just distilled water showed no change in the gas height, indicating that no respiration took place. In the second part of the experiment, the setup containing the soaked beans had a yellow color, while the setup containing the beans that were both soaked and boiled remained red,