Peroxidase Lab Report

Discussion Our results indicate that the presence of iron increases the rate of the peroxidase’s activity, judging from the increase in absorbance with increasing amount of iron. This result supports our hypothesis that the iron acts as a cofactor in peroxidase’s activity and results in the faster rate of the reaction. Also, we assumed that the more we put iron in the solutions, the faster the rate is. This assumption is also supported by the results that higher concentration of iron cofactors shows the higher absorbance. The importance of the existence of iron in this reaction is that the peroxidases in plant cells respond to environmental stress by, in this case, catalyzing the conversion of toxic metabolic wastes, H2O2, into the harmless products, H2O and O2, faster. Therefore, as peroxidases help minimize and eliminate harmful chemicals, the iron cofactors that help peroxidase’s activity raise the possibility of plants’ survival in harsh environments.
First of all, as shown in the result, at 120 seconds, cuvette 4s (0.75 mL of iron) do not show as big differences between cuvette 3s (0.50 mL of iron) as between other cuvettes, for example, absorbance differences between cuvette 1s and 2s or 2s and 3s. It is assumed that the relative concentration of enzymes does not catch up that of iron cofactors. In other words, even though we put more iron cofactors to interact with enzymes after a certain point, it cannot speed the reaction further because no more enzymes can interact with extra iron cofactors. Furthermore, we can notice that even though the higher amount of iron cofactors indicates the higher absorbance over time, the changes of the higher amount of iron cofactors from 0 to 120 seconds are not larger than that of the smaller amount one, especially cuvette 1s. It is concluded that the peroxidases and iron cofactors underwent the reaction so fast that it occurred before we measured by using the