Determining the optimal temperature and pH of alpha-amylase and starch solution.
A catalyst is the chemical agent that changes the rate of a reaction without being consumed by the reaction. A cell's physical and chemical environment affects enzyme activity. The activity of an enzyme is affected by general environmental factors, such as temperature and pH. Because the three-dimensional structures of proteins are sensitive, an enzyme has conditions under which it works optimally. Using absorbance readings, reaction rate and optimal levels can be concluded. .
The purpose of this experiment is to observe for 20 minutes the effect of temperature and pH on the reaction of α-amylase with starch and to establish the optimum temperature and pH for this reaction. I hypothesize that the optimal temperature and pH will be 30 C and 4.5, respectively. .
After setting the spectrometer to 560 nm, the temperature blank solution was prepared. It consisted of 0.1 ml of I2KI and 5 ml of distilled water in a glass cuvette. The spectrometer was calibrated with the blank cuvette. Then I prepared a mixture of 35 ml of starch and 35 ml of distilled water in a flask. I placed this solution into a water bath to achieve 70°C. Then 11 cuvettes were each filled with 0.1 ml of I2KI . Next 5 ml of the 70 ml solution was measured into one of the 11 cuvettes and placed in the spectrometer to measure the absorbance. After the initial reading, one ml of α-amylase was dropped and stirred into the to 70 ml solution. The addition of this enzyme started the 20 minute time interval for which I would be measuring. Every minute for the first 10 minutes and then again at the 20 minute interval, five ml of the 70 ml solution was added to one of the 11 cuvettes containing 0.1 ml of I2KI, and the absorbance was measured. This entire .
experiment was repeated five more times at the following temperatures: 15°C, 30°C, 45°C, 55°C, and 60°C.
