What is the expected outcome in the presence of a reduced sugar?

What is the expected outcome in the presence of a reduced sugar?

What is the expected result when a reducing sugar is present?

Fehling’s Test When reducing sugars have been added, the solution will begin to change color as a rusty or red precipitate. The solution will stay blue or green if there are no reducing sugars.

What color difference will be observed in glycogen with iodine test?

Glycogen is structurally quite similar to amylopectin, although glycogen is more highly branched (8-12 glucose units between branches) and the branches are shorter. Glycogen can be treated with iodine to give it a reddish-brown color.

What color difference will be observed in glycogen with iodine test or how can iodine test be used to distinguish between amylose and glycogen?

In the presence of starch, Lugol’s Iodine gives off a blue-black colour. Lugol’s solution reacts with Glycogen to produce a brown-blue colour. The color of other polysaccharides or monosaccharides does not change. The test solution is still the same brown-yellow as the reagent.

What is the iodine test used for?

The iodine blood tests are useful for diagnosing iodine deficiency (or excess), iodine induced hyperthyroidism and hypothyroidism, and autoimmune thyroid diseases like Graves’ disease or Hashimoto’s thyroiditis. They also monitor exposure to iodine.

Why do all sugars give a positive Molisch test?

All carbohydrates (monosaccharides/disaccharides/polysaccharides), give positive reactions to the Molisch test. This test is based upon the dehydration by Sulphuric Acid of carbohydrate to produce an aldehyde. The aldehyde condenses with two molecules a-naphthol and forms a purple ring at interface.

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What is the principle of Seliwanoff test?

This test is based on the principle of ketoses being more quickly dehydrated when heated than aldoses. Theodor Seliwanoff is the name of the chemist who developed the test. A rapid formation of a red color occurs when the test is added to a solution that contains ketoses.

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