Question

Explain the reaction between iodine solution and polysaccharides by giving the structure of related compounds

Answer 1

Answer:

The presence of starch may be detected using an iodine test. Starch interacts with iodine solution (iodine dissolved in an aqueous solution of potassium iodide) to produce a blue-black hue.

Answer 2

Iodine test is a chemical test used to distinguish mono or disaccharides from certain polysaccharides like amylase, dextrin, and glycogen.

Explanation:

• Although the polysaccharides reacted to give a dark blue starch like coloration with iodine, potentiometric titration showed that only the xylan was complexed with iodine in a manner similar to that of amylose while galactoglucomannan and “amyloid” bound iodine in a looser fashion typical of poly(vinyl alcohol).
• Using iodine to test for the presence of starch is a common experiment.
• A solution of iodine and potassium iodide in water has a light orange brown color. If it is added to a sample that contains starch such as the bread pictured above the color changes to a deep blue.
• Iodine test is a chemical test used to distinguish mono or disaccharides from certain polysaccharides like amylase, dextrin and glycogen.
• This test has a variation termed starch iodine test that is performed to indicate the presence of glucose made by plants in the leaves.