All living organisms obtain their energy from the environment through various processes. An example is a cellular fermentation, a pathway of breaking down sugars in the absence of oxygen. Yeast is one of the organisms that perform this procedure in the presence of a substrate to produce energy. The process also occurs in the muscle cells of animals when performing a vigorous activity and in bacteria. In alcohol fermentation, sugars are converted into carbon dioxide, ethanol, and other by-products.
This is the basis of manufacturing alcoholic drinks such as beer and wine. In lactic acid fermentation, pyruvic acid combines with electrons donated from NADH to form lactic acid and NAD+. Different types of sugars can be used by yeast for fermentation. Monosaccharides are simple sugars that are easily processed to produce energy. Disaccharides can be broken down into monosaccharides and used as a source of energy. Polysaccharides such as starch have long chains of glucose monomers linked by α glycosidic bonds. These links are digested to make the sugars available as an energy source.
However, some polysaccharides such as non-starch polysaccharides or resistant starch cannon are digested. Experiments were done to provide a better understanding of fermentation. In this lab, the amount of gas produced at different temperatures was measured. The hypothesis was that an increase in temperature causes an increase in fermentation. The dependent and independent variables were fermentation and the amount of gas formed, respectively.
The temperatures used were 370C, 250C, and 40C, and water was used as a control experiment. The volume of gas produced was measured after every 5 minutes and then compared after 40 minutes. In water, 0mL of gas was formed at every temperature while sucrose produced 0.5, 2.2, and 5mL at 40C, 250C, and 370C, respectively. From the results, it is evident that temperature affects fermentation. At temperatures of 40C, there was little gas production, while maximum gas production occurred at 370C. At low temperatures, the cells are inactive hence decreased fermentation. An increase in temperature promotes the growth of yeast cells and increases their activity.
Work Cited
Upadhyaya, Ashok. Cellular Processes Laboratory Manual. The University of Texas, n.d.