Yeast Fermentation essays

Yeast Fermentation essays Effects of Various Carbohydrate Substrates on Yeast Fermentation This experiment was performed to determine which carbohydrate substrates positively influence yeast fermentation since yeast seems to have greater ability to utilize certain carbohydrates. Rate of evolution of carbon dioxide was measured by the amount of carbon dioxide produced over time. We compared the reaction rates in samples with varying carbohydrate substrates at a constant temperature of 35 degrees C. The most efficient carbohydrates, with respect to time and energy, were the ones best suited for the yeasts enzyme-based transport system (Vilet, 1993), which allows entry into the yeast cell and entry into the glycolytic pathway. Those carbohydrates best suited for the enzyme-transport system had the highest carbon dioxide levels and the greatest reaction rates. For millennia, humans have used the alcoholic fermentation capability of yeast to produce breads, crackers and a variety of fermented beverages including beer and wine. Yeast are versatile unicellular fungi. They grow rapidly and have simple nutritional requirements. When yeast degrade nutrients in the absence of oxygen they use the process of glycolysis to produce energy in the form of ATP (Klocker, 1901). In this process, known as yeast fermentation, there are 2 ATP molecules produced for each glucose molecule fermented. The products from one glucose molecule are two molecules of ethanol and two molecules of carbon dioxide (Jorgensen, 1911). A rapid reaction rate and increase in the products released depend on the carbohydrates compatibility with the yeasts enzyme-based transport systems. This transport system, associated with the cell membrane, allows yeast to bring selected carbohydrates into their cells. In this experiment we tested the effect of several carbohydrate substrates on yeast fermentation. Our foc ...