The Determination of Optimal Temperature, pH, and the Reaction Rate for Alpha-Amylase.
The enzyme alpha-amylase is a catalyst to break up starch to from glucose. Without being consumed in the reaction, enzymes are catalysts that speed up the rate of the reaction. They achieve this by combining with a substrate and then separating from it form products. Environment factors that affect enzyme reactions include temperature and pH. The optimal temperature and pH at which the reaction will occur coincides with the point where the rate of reaction is at maximum value. The purpose of this experiment was to determine the ideal temperature, pH, and fastest rate for alpha-amylase. This was performed using I KI as an indicator of the complex and a spectrophotometer to read the measurements at a temperature range from 15-70°C and a pH range of 4.0-6.5. Readings of starch concentration were then taken over a twenty minute interval. The experimental results indicate that the optimal temperature is 50° and the optimal pH is 5.0. Enzymes are a class of proteins serving as catalysts, chemical agents that change the rate of reaction without being consumed by the reaction (Campbell, 1996). Enzymes can increase the rate at which efficient reactions occur (Vliet, 1993). The reacting molecule o
I used I KI indicator for this experiment because of its property of forming a blue-black complex with starch that indicates its presence and stops its reaction with alpha-amylase. The spectrophotometer was set at a constant frequency. First, I added 0.1 ml of I KI to 12 cuvettes. By adding 5ml of distilled water to the first cuvette, a "blank" was created. It was used to set the spectrophotometer to zero absorbency. Next, I combined 35ml of stock starch (0.0033 g/ml) with 35ml of distilled water in an Erlenmeyer flask. I transferred 5ml of the solution into the second cuvette and took a time zero reading from the spectrophotometer. Concluded from the results of the experiment, alpha-amylase most efficiently reacts with starch at a temperature of 50° and at a pH of 5.0. The maximum reaction rate was .078ml/min. The results for the temperature trials showed the optimal temperature to be 50°C, differing from my hypothesis by 5°C. The results for my pH trials proved my hypothesis as the optimal pH to be 5.0. The purpose of this experiment was to determine the optimum temperature and pH for the reaction of starch with the enzyme alpha-amylase. I hypothesize that the optimal temperature will be around 45° C because it will be just enough to heat up the molecules and speed up the reaction without altering the tertiary structure of the enzymes. I hypothesize that the reaction will be the highest at a pH of 5.0. This is because a slightly acidic environment will speed up the rate of the reaction. The results of the temperature experiment are displayed on Figure 1; a best-fit curve was then drawn for the varying temperature trials. The data for the 15°C curve did not fit well. While the 45°, 55°, and 60°C curves were smooth and steadily declining. Alpha-amylase is and example of such an enzyme. This enzyme is found in germinating barely seeds. It is synthesized and released fro
Some common words found in the essay are:
INTRODUCTION Enzymes, Procedure KI, DISCUSSION Concluded, Reaction Rate, , reaction rate, Campbell NA, temperature ph, vliet 1993, optimal temperature, rate reaction, Vliet KA, Heights Massachusetts, distilled water, optimal ph, ph 50, tertiary structure, best-fit curve, best-fit curve drawn, Biology BSC, instead distilled water, solutions instead distilled, temperature ph reaction, tertiary structure enzyme,
Approximate Word count = 1286
Approximate Pages = 5 (250 words per page double spaced)
|
