Image credit schule-bw.de

Image credit schule-bw.de

ZIMSEC O Level Combined Science Notes: Amylase enzyme experiment

Experiment

Materilas: 1% amylase enzyme/saliva, 2% startch solution, visking tubing, reagents to test for starch and sugar, beakers.

Method A: Visking Tubing.

  • NB. The Visking Tubing is used to function/work as a small small intestine.
  • Prepare two model intestines by wetting the visking tubing.
  • Open the ends of the tube. Tie one end tightly with a string to make a bag like structure.
  • Add 5 to 10 ml of starch solution and the same amount of enzyme solution/or gurgle an amount of the solution and spit it into one tube and label it tube A.
  • Add only starch solution to the other and label it tube B.
  • Remove a small sample of the mixture for testing. Keep this to one side.
  • Was the outside of the bags carefully to remove ony of the solutions and make sure the bags are not leaking.
  • Support the bag in a small container of water or tie the other end tightly and immerse in water.
  • Test the content of the bag and the surrounding water for starch and reducing sugar at the start of the experiment.
  • Repeat after about 10-15 minutes.
  • Record the results.

Results

  • Test tube A’s starch is converted into reducing sugars.
  • The starch in test tube B remains unchanged.
The contents of tube A are the right and Tube B on the left.

The contents of tube A are the right and Tube B on the left. Image credit studyblue.com

  • The results shown above are obtained after carrying out a test using Benedict’s Solution which is used to test for the presence of reducing sugars.
  • The contents of Test Tube A (to the right) show the presence of reducing sugars. The solution turns brick red in colour. This is because the enzyme amylase has acted as a catalyst resulting in starch being converted into reducing sugars.
  • The contents of Test Tube B show that the starch has remained unchanged.
The contents of tube A are to the right and those of Tube B above to the left. Image credit  sites.google.com

The contents of tube A are to the right and those of Tube B above to the left. Image credit sites.google.com

  • When a test for starch is carried out using an Iodine solution the following results are obtained:
  • The contents of Test tube B turn blue-black as above and showing that the starch remains unchanged.
  • The contents of tube B above show that there is very little starch after the experiment as most of it has been turned into reducing sugars.

Conclusion

  • Amylase acts as a catalyst during the digestive process.
  • This results in the starch in food being turned into reducing sugars.

To access more topics go to the Combined Science Notes page.