The Effects of Temperture on Yeast Growth and Fermentation

Introduction The purpose of this experiment is to determine the effect that temperature has on the growth and respiration of yeast fermentation. The growth and respiration of the yeast can be determined by using a glucose/ yeast solution mixed with water in flasks set at different temperatures. Yeast in order to produce, has to make energy, to carry out all cellular functions (Spicer, & Holbrook, 2007). The concept that aerobic metabolism of all yeasts, is determined by the relative sizes of the transport rate of sugar into the cell and the transport rate of respiratory into the mitochondrion. (Barford, 1990) “Yeast is of various one-celled fungi that can cause the fermentation of carbohydrates, which can lead to producing carbon dioxide and alcohol. (Ashe, 1998). By monitoring the temperatures that the yeast mixture is in, one can study the growth and respiration rate (by the measurement of H20) in a water displacement. “Glucose is a syrupy mixture of dextrose, maltose, and dextrin’s containing about 20 percent water, used in confectionery and alcoholic fermentation” (Guthrie, & Fink, 2002). In order for fermentation to occur sugar or also known as glucose must be present within the yeast. When the yeast fermentation solution was used it made it easier to measure the effects of temperature on the yeast fermentation and the respiration or breathing room of the yeast and meets the lab requirements. Also yeast when combined with sugar excretes carbon dioxide in which was measured through the process of water displacement.
Water displacement is when something is placed in water and the amount of water is measured (Hughes, 2005). This is because when there is growth present the water levels increase to make room for the foreign object or substance in which in this case is carbon dioxide. Cellular respiration is a chemical process in which breaks down sugars into water and carbon dioxide. The equation for cellular respiration is as followed C6H12O6 + 6O2 -->

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