Enzyme Activity
Aim:
The purpose of the activity is to explore some of the factors that influence the rate of enzyme activity in an organism.
Hydrogen Peroxide
(H2O2)
Hydrogen Peroxide (H2O2) and Catalase Hydrogen Peroxide (H2O2), Acid and Catalase Hydrogen Peroxide (H2O2), Base and Catalase Hydrogen Peroxide and Cold Catalase Hydrogen Peroxide and Boiled Catalase Starting O2 (%) 21. 4 22. 1 22. 1 22. 6 21. 9 23. 3 Ending O2 (%) 24. 5 71. 7 35. 6 48. 2 71 25. 4 O2 Difference (%) 3. 1 49. 6 13. 5 25. 6 49. 1 2. 1 Discussion:
1. From the graph, it can be seen that graph A (hydrogen peroxide without catalase) is gentle while the graph B (hydrogen peroxide with catalase) is steep. This illustrates how the enzyme affects the rate of reaction. The presence of enzyme speeds up the rate of reaction at which catalase enzyme converts hydrogen peroxide to water and oxygen. As the rate increases, the amount of oxygen produced increases. Therefore, there is a high rate of enzyme activity as more oxygen is being converted.
2. One of the factors affecting enzyme-catalysed reactions is the effect of pH. Adding the base (sodium hydroxide) to the solution of peroxide raises the pH of the solution and slows down the rate of reaction of the enzyme used for decomposition reaction of hydrogen peroxide. This means that the enzyme is less efficient. Like other enzymes, catalase can only work best and fastest in the right environment. Catalase works best when the pH is neutral, which is between 7. 3 to 7. 4. Since sodium hydroxide is added, the pH will go up and deviates from the normal range. As the pH gets higher, meaning that it goes further from the normal environmental conditions, the enzyme will become inactive and in extreme conditions, might lose its shape and become denatured. When this happens, the reaction will come to a halt and thus, disabling the enzyme to break down peroxide. From the table, it is clearly shown the hydrogen peroxide without base creates more oxygen (71. 7%) at the end of the experiment, while the hydrogen peroxide with base creates 48. 2%, with a difference of 23. 5%. Lower oxygen produced shows that the sodium hydroxide has decreased the rate at which the enzyme works. In addition, as seen from the graph, the hydrogen peroxide with base is much slower than hydrogen perox...
