Experiment 4: Effect of Temperature on Enzyme Activity
Aim:
To determine the effect of temperature on enzyme activity
Introduction:
Enzymes are biological catalysts which are made up of protein. A catalyst is a kind of substance that alters the rate of chemical reaction without being altered itself. Enzymes convert the substrates into products by chemical reaction. This required a specific reaction as the active site of the enzyme can only bind with specific substrate molecule.
The specificity of the enzymes is because the complementary nature of the substrate and the active site of the enzyme. A part on the surface of an enzyme which has a particular shape and let a substrate molecule with a complementary shape fit in it is called an active site. If the shape of a substrate molecule is not complementary to the active site of the enzyme, the substrate molecule cannot be broken down.
Due to their protein nature, enzyme catalyse reactions under a narrow range of environmental conditions can easily interfere their reaction. One of the factors that affect the activity of enzyme is the temperature. Different enzymes operate best at different temperature.
Materials:
Starch solution, sodium chloride, amylase solution, water bath, test tube, iodine, white tile, stopwatch and dropper
Method:
1. A 30ºC of water bath was set up.
2. 3cm of starch solution and 1cm of sodium chloride were added into a test tube while 2cm of amylase was added into another test tube.
3. The two test tubes were left in the water bath for three minutes.
4. A few drops of iodine were prepared on a clean white tile.
5. The two solutions were added into one tube and the test tube was left in the water bath. The time taken was recorded immediately.
6. Every one minute, few drops of the mixture were taken to test with the iodine drops prepared. This was done until the colour of the starch disappeared.
7. Steps one to six were repeated by replacing the...