Effect of inhibitors on the action of amylase

To Study The Effect of Effect of Inhibitors on the Action of Amylase

Inhibitors are substances that slow down or stop enzymes. Competitive inhibitors are molecules that are very similar to the substrate, so they can bind to the enzyme but cannot react. They compete with the substrate for the active site of the enzyme.

Noncompetitive inhibitors are molecules that are not similar to the substrate and therefore do not bind to the active site. They do, however, bind to a different location on the enzyme and change the shape of the active site so that the substrate can no longer bind. Irreversible inhibitors form covalent bonds to the enzyme and therefore cannot be removed.

 Procedure

 1.     Place 4 mL of amylase solution in each of three test tubes.
2.     To the first tube, add drops of 1 % NaCl solution.
3.     Add 10 drops of 95 % ethanol to the second testtube.
4.     Add 10 drops of either AgNO3 or Pb(NO3)2 solution to the third test tube.
5.     In each of three separate clean test tubes, place 4 mL of 1 % starch.
6.     Place all six test tubes in the 37°C water bath for 5 minutes.
7.     When the 5 minutes is up, pour a tube of starch solution into each of the enzyme-inhibitor mixures.  

8.     Mix each tube and return the tubes to the water bath for 15 minutes. Meanwhile, rinse out three droppers. 

After 15 minutes, transfer 4 drops of each mixture (using a clean dropper each time) to a spot plate.

10. Add 1 drop of iodine reagent to each sample.

11.  Record your observations and the enzyme activity level in each case.