Class: BE-210
Group: R5
Members: Erin Butler, Elizabeth Hamme, Alexander Taich, Bryan Wells
Date: April 30, 1998
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Abstract:
The purpose of this experiment was to determine the buffering capacity of hemoglobin and to compare its buffering capacity to that of ovalbumin and potassium phosphate. Additionally, the total number of buffering sites for each of these proteins was determined and compared. A Fisher Scientific Accumet Model 925 pH meter was used to measure the pH of several solutions so that titration curves, the buffering capacity, and the number of buffering sites could be obtained. Hemoglobin was found to have the greatest buffering capacity per mole of 7.17*10^7 + 1.31*10^7 over a pH range of 5.5 to 9, as compared to 2.6*10^7 + 5.54*10^6 per mole of ovalbumin and 4.9*10^6 + 2.45*10^5 per mole of potassium phosphate. It was also determined that hemoglobin had the greatest number of buffering sites per mole of 32.27 + 2.23, as compared to 13.1 + 2.63 sites per mole for ovalbumin and 0.92 + 0.05 sites per mole for potassium phosphate. There was found to be a direct relation between buffering capacity and the number of buffering sites, and the values for the number of buffering sites corresponded very closely to the theoretical values.