Enzyme Activity Lab Report

The prediction for the effects of temperature on the enzyme activity was that the reaction’s rate would increase as the temperature increased, until they go over the optimum temperature where the enzymes denature and the reaction’s rate quickly drops to zero. At 5 degree C the rate is 0.00059mole PNP/min. This then increases to 0.01031mmoles PNP/min at a temperature of 50 degree C. The rate then drops drastically to -0.00215moles PNP/min. This point is where the enzymes have been denatured and have no activity, shown as the last point on the fig 8 and 9, do not fit on the graph. The optimum temperature was about 47 degree C. The core body temperature is only about 37 degree C and thus these enzymes are operating below their optimum temperature.
The optimum pH for the enzyme acid phosphatase was predicted to be within acidic regions and the results obtained showed that the optimum pH was about 5.5 see fig.10. It had the highest absorbance value, meaning it had the most PNP in the tube in the given time and thus the fastest rate of reaction. A change in pH changes the shape of the active site of the enzyme. The bonds within the active site of the enzymes are polar, this means that they are extremely sensitive to ions. The decrease in pH increases the concentration of H+ ions in the solutions, these interact with the polar bonds in the enzymes structure to form individual bonds. This disrupts the shape of the active site and thus the substrate PNPP is no longer complementary to the enzyme’s active site. So no Enzyme substrate complexes can be formed and the rate of reaction drops. The same thing happens when there are extra OH- ions in the mixture. The pH in our cells must be extremely specific and buffered in order to prevent changes in pH and the denaturing of these enzymes. The data collected during these experiments are very similar to those published and studied, meaning the results collected are valid, and thus the experiment