Plants store glucose as the polysaccharide starch; the cereal grains (wheat, rice, corn, oats, barley) as well as tubers such as potatoes are also rich in starch. Starch can be separated into two fractions--amylose and amylopectin. Natural starches are mixtures of amylose (10-20%) and amylopectin (80-90%).
Introduction
Amylose forms a colloidal dispersion in hot water whereas amylopectin is completely insoluble. The structure of amylose consists of long polymer chains of glucose units connected by an alpha acetal linkage. Starch - Amylose shows a very small portion of an amylose chain. All of the monomer units are alpha -D-glucose, and all the alpha acetal links connect C #1 of one glucose and to C #4 of the next glucose.
As a result of the bond angles in the α acetal linkage, amylose actually forms a spiral much like a coiled spring. See the graphic below, which show four views in turning from a the side to an end view.
Answer: amylase breaks down carbohydrate (starch) .
Explanation:
Iodine is a dimer molecule and when it reacts with starch which is a glucose, it forms deep blue color. In the presence of amylase a digestive enzyme which breaks down starch, comes in contact with the solution, it breaks down the carbohydrate and iodine polymer chains are broken down, and the [blue/black] color disappears.
This experiment is used to test the effect of digestive enzymes on foods (carbohydrates) in this case.
