Effect Of Sucrose Concentration On Yeast Fermentation

Abstract All living organisms use their environment to gain energy needed to survive. Cellular respiration is one way this occurs. Cellular respiration happens as enzymes react to other molecules, like fats and carbohydrates, to produce energy. Fermentation occurs when sugar is present resulting in chemical energy. Yeast, a type of fungus, carries out fermentation in the presence of a sugar. This process can occur with oxygen (aerobic) or without oxygen (anaerobic). An experiment can be conducted to better understand the process. The observation of how yeast ferments and produces carbon dioxide when combined with various sugars is one way to better understand fermentation. With the use of a respirometer, the rate of fermentation produced

This is because lactose is a disaccharide. Lactose must be broken down into monosaccharides before fermentation can occur. Lactose fermentation usually produces very little cellular respiration in yeast (Schuster, VanZyl, & Coller, 2005). Sucrose had the highest rate of fermentation for 1%, 5%, and 10% concentrations. Since sucrose is a combination of glucose and fructose, one would expect a faster reaction (Pepin & Marazzacco, 2015). According to Matsushika, Nagashima, Goshima & Hoshino (2013) yeasts such as Saccharomyces cervisiae cannot naturally utilize xylose for growth or fermentation. It is also possible that the carbon source of xylose changes the metabolism during anaerobic conditions (Matsushika, et al., 2013). These are possible explanations for the zero results for the sugar xylose. Glucose had the second fastest fermentation rate compared to the others. Yeast ferments well with monosaccharides, so this result was expected. From the beginning of the experiment, it proved to have a steady increase.
The hypothesized prediction that sucrose would have a higher fermentation rate than the other sugars was correct. Sucrose had a fermentation rate that was more than twice the rate of any other sugar tested. The 10% concentration was more than three times faster than the next closest sugar, glucose. When comparing disaccharides to monosaccharides, the component of the disaccharide directly affects the fermentation rate, as seen by the slowest sugar