Specificity of amylase and sucrase enzymes action.

The polysaccharides, such as starch and glycogen are specific substrates for amylase. The sucrose disaccharide serves as a substrate for the sucrase enzyme. The hydrolysis process with enzymes being present can be found in Trommer’s test that is not given by the initial carbohydrates.

They enumerate four test tubes. 2 ml of starch solution are poured into test tubes number 1 and 2; and 2 ml of sucrose solution are poured into test tubes number 3 and 4. 0,5 ml. of saliva solution are added to test tubes number 1 and 3, and 0,5 ml. of 1% yeast sucrase solution are added to test tubes number 2 and 4. Everything is mixed and placed in the water bath at a temperature of 38-40°С for 10 minutes. After cooling they test reactions with iodine to find starch in tests number 1 and 2 and then use Trommer’s test to find glucose in tests number 3 and 4. The final step is making a conclusion about the specificity of the learned enzymes.

sucrose glucose glycoside hydroxiles fructose

Test questions

1. What is the role of enzymes in an organism?

2. What class of chemical compounds do enzymes belong to?

3. What class do the enzymes used in the laboratory work belong to?

4. Why does inactivation of the enzymes solutions take place while boiling them?

5. How can you explain the specificity of sucrase and amylase enzymes? How can it be proved?

6. How does the lowering of pH influence the activity of α-amylase? Why?

7. On what principle is the qualitative definition of enzymes based on?

Laboratory work 5. Identifying the activity of enzymes