To determine the effects of stressful experimental treatments on living membranes we are going to examine how fresh beets roots react when they are exposed to different temperatures. Membranes are an important feature of plant cells and they act as a barrier that separates the interior of the cell from the external environment (Campbell 133). They organize specific chemicals and reactions into specific compartments within the cell. Generally, cell membranes consist of phospholipids bilayer that is impermeable to most polar molecules because of its hydrophobic interior . Moreover, phospholipids show hydrophilic and hydrophobic properties, which means the head of the molecule is attracted to water and the tail excludes water and other polar molecules from interacting (Kono 7101). However, if given enough time, we can observe that almost any molecule will diffuse across the bilayers. The aim of this experiment is to investigate the integration of the cell membranes. Cell membranes are an important part of the living system; therefore, they are sensitive to environmental conditions. Their functionality changes with respect to the environments such as temperature (Maynard G. Hale) . In the experiment, we use the red beets in order to see how the structure of the membrane relates to its function. Red beets cells contain central vacuoles that house a pigment called Betacyanin. When beet cells remain intact, Betacyanin stays within the cell. Once the beet cells are disrupted, betacyanin will leak out and create a pink/red color in the environment. An increase in membrane damage will cause more betacyanin leakage; hence, we will see a higher absorbance reading on the spectrophotometer. Thanks to betacyanin release and measuring absorbance we can conclude how much the cell membranes are damaged. In this experiment, we expose beet cell to two different environments. First, we determined the maximam wavelength absorption. by measuring the betacyanine in the spectrometer. Second, we tested the effect of temperature ranging from -20 C to 70C on beet cells. We hypothesize that exposure to higher temperatures (70C) and lower (-20C) will have a severe effect on the cell membranes in Beta Vulgaris (Beet Cells) and it will result in betacyanin higher leakage.. Methods
First , we need to determine the standard wavelength by measuring a prepared betacyanine solution in the spectrometer (the betacyanine solution was made by mixing the pigment with dH2O)(lab manual pg. 42). The betacyanines’ absorbance was measured in the spectrometer at a different sets of wavelengths (400,425,475…,700). The measurements were recorded and the maximum absorbance was used as a standard wavelength which it appeared to be A525(Figure 1).
Figure #1 betacyanine solution was measured in different sets of wavelength in the spectrometer, it presented different absorbance.
second , we cut the fresh beet root into 5 small equal pieces 5 mm each, and one piece (-20C) was handed by the instructor. The 6 pieces were used for the temperature treatment . the 5 beet discs were carefully washed under relatively warm tap water(15°C-18°C) for 10 minutes to clean the leaked pigment. At the same time we labeled 6 big test tubes from “A” to “F”. 6 test tubes were filled with 10 ml distilled water. Each of the 5 beet root discs were placed in each of the given tubes and were submerged in (-4°C,25°C,40°C,55°C,70°C) respectively for 1 minutes. The discs in tubes “B” to “F” followed the same pattern for the respective temperatures except the one at -20C, which was placed in the tube immediately after the disc was obtained. Each disc remained in the tube for about 15 minutes and during the extraction each tube was gently vortexed every 5 minutes. After 15 minutes we transferred about 5 ml of water with the released pigment from the big test tube to a 1cm cuvettes. The cuvette was placed in the spectrophotometer in...
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