In PhysioEx Exercise 2, Activity 3, the goal is to investigate the effect of temperature on enzyme activity. Enzymes are proteins that catalyze chemical reactions in the body, and they are sensitive to changes in temperature. This activity allows students to observe the effects of temperature on the activity of the enzyme catalase, which is found in liver cells and helps to break down hydrogen peroxide.
To begin the activity, a sample of liver tissue is homogenized in a buffer solution to extract the catalase enzyme. The enzyme solution is then placed in a spectrophotometer, which measures the amount of light absorbed by the solution at a specific wavelength. The spectrophotometer is used to measure the rate of the reaction catalyzed by the enzyme, as the rate of the reaction is directly proportional to the amount of light absorbed by the solution.
The activity consists of three experiments. In the first experiment, the effect of temperature on the activity of the enzyme is investigated by measuring the rate of the reaction at four different temperatures: 10, 25, 37, and 50 degrees Celsius. The results show that the rate of the reaction increases as the temperature increases, reaching a maximum at 37 degrees Celsius. Above this temperature, the rate of the reaction decreases as the enzyme becomes denatured and loses its activity.
The second experiment investigates the effect of pH on the activity of the enzyme. The pH of the enzyme solution is adjusted to five different levels: 3, 5, 7, 9, and 11. The results show that the enzyme has a optimal pH at which it is most active, which is around 7 in this case. At pH levels outside of this range, the activity of the enzyme decreases.
The third experiment investigates the effect of substrate concentration on the activity of the enzyme. The substrate is the substance that the enzyme acts on to catalyze the reaction. The substrate concentration is increased in five steps, and the rate of the reaction is measured at each concentration. The results show that the rate of the reaction increases as the substrate concentration increases, until it reaches a maximum value. At higher substrate concentrations, the rate of the reaction remains constant as the enzyme becomes saturated with substrate.
In conclusion, the activity of enzymes is influenced by a variety of factors, including temperature, pH, and substrate concentration. Understanding how these factors affect enzyme activity is important for understanding the mechanisms of chemical reactions in the body and for developing drugs and other therapies that target enzymes.
