The aim of the investigation was to determine the effect of pH on the rate at which catalase decomposes hydrogen peroxide and consequently answer the researchable question “How does pH influence cells and consequently an organism”.
The hypothesis, “As the pH deviates from 7 the initial rate of oxygen production will decrease” is supported by the results. The trend displayed in Figure 3 is, as the pH deviates from 7 the initial rate of reaction decreases. Figure 3 shows that the rate of reaction (%O2/s) decreases substantially as the pH increases and decreases to 8 and 6 respectively from a pH of 7. This is indicated as the graph shows that the initial reaction rate for pH 7 was 0.143 %O2/s compared to 0.047 and 0.053 for pH 6 and 8 respectively. Additionally, Figure 3 indicates that as the pH increases or decreases from 8 and 6 respectively the initial rate of reaction decreases marginally. This is known as the initial rate of reaction for pH 4 and 10 was 0.036 and 0.035 %O2/s, indicating an unsubstantial difference in the initial rate of reaction; for pH 4 and 6 of 0.011 %O2/s and pH 8 and 10 of 0.018 %O2/s. As the pH deviates from 7 the initial rate of reaction decreases as the optimal pH for catalase is 7. As the pH increases or decreases the concentration of hydrogen and hydroxide ions in the solution are altered. These ions alter the shape of the enzyme diminishing the ability for hydrogen peroxide to bind with the active sight of the catalase enzyme in turn decreasing