Research paper on Effect of Acidic and Alkaline Medium on Amylase Activity

Research paper on Effect of Acidic and Alkaline Medium on Amylase Activity

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Enzyme: Amylase

Amylase is an enzyme that is essential for the breaking down of starch. For humans, digestion of starch begins in the mouth, and the salivary amylase in saliva present catalyzes this. Being the first enzyme to be discovered and isolated, many experiments have been done to evaluate its properties. The pancreas also produces amylase. Its role in digestion is to break down the starch into disaccharides and trisaccharides.

Being an enzyme, amylase is a protein in nature and requires stability of its structure to maintain its function. Exposure to heat and unsuitable pH will result in changes in its three-dimensional structure. Consequently, there will be reduced or impaired functions.

Objective

To determine the effect of low pH (increased hydrogen ion concentration) on the activity of amylase enzyme.

            Amylase is normally present in biology laboratories and exists in the form of powder. However, the powder is considered harmful due to its ability to degrade any substance that consists of starch. 1% concentrations are preferred to reduce this. For this experiment, the preferred source of amylase is human saliva. It will further enlighten, and train students on safety precautions since saliva as a body fluid may transmit diseases.

Requirements

The following items will be needed to complete this experiment.

6 test tubes

5 ml of distilled water

10 ml of saliva

6 ml of pH buffers {citric acid/ sodium citrate and Tris (hydroxymethyl) aminomethane / Hydrochloric acid}

5 ml of iodine solution

4 ml of starch solution

Dropper

Stopwatch

Procedure

pH buffers are to be prepared with pH values of 3, 5, 6, 7, 8 and 9. Citric acid/ sodium citrate buffer is the most suitable for the development of acidic buffers while Tris (hydroxymethyl) aminomethane / Hydrochloric acid is favorable for alkaline. They are put in 4 different test tubes. A mixture of starch and amylase are added to the test tube that contains distilled water. The same amounts of the mixture are also added to each of the four tubes containing pH buffers that were initially prepared. Iodine solution is then added to each of them and time recorded for the color to change from brown to blue-black. The time recorded directly reflects the rate of the reaction.

Expected Results

Amylase has a pH of 5.3 meaning that it is slightly acidic. For pH less than 5.3 (3 and 5), the rate of the reaction is expected to be moderately high. Peak activity is obtained at 5.3 for this sample. Above pH value of 5.3, the rate of the reaction decreases steadily. Most other enzymes and pancreatic amylase have an optimal functionality at pH around 7.0. For salivary amylase, it is expected that pH above 5.3 will reduce its acidicity in an attempt to neutralize the enzyme. Consequently, it denatures the enzyme by affecting its three-dimensional structure just as it happens with temperature changes.

Caution

By using human saliva, caution should be highly taken to ensure that transmission of diseases is limited, if not prevented, by handling using gloves. Smelling the samples should equally be avoided to prevent airborne infections such as tuberculosis.

Principles

The buffers should be tested using the pH tester to ensure they correspond to the required pH levels and to ensure the accuracy of the findings.

            The amylase obtained should be stored at favorable temperatures before use to limit interference with its three-dimensional structure. It is also to ensure that the enzyme maintains its functional properties.

            Salivary amylase works best at pH between 4.7 and 5.3 whereas that of the pancreas is between 6.7 and 7.0. When pancreatic amylase is used as the sample, the results are likely to be different but will still apply the same principle.

Conclusion

At optimal pH, different enzymes function at their best regarding functionality and rate. When exposed to extreme conditions, they become denatured, and their functions are limited. Other factors that affect enzyme functions are temperature and heavy metals.