Question

Glycosaminoglycans (GAGs) are heteropolysaccharides composed of repeating disaccharide units. These units have some similar characteristics that allow them to be identified as GAGs. Which of the following are examples of glycosaminoglycans? Select all that apply.

Answer 1

Concepts and reason

The concept used to solve the given problem is the knowledge of Glycosaminoglycans. The Glycosaminoglycans are the unbranched polysaccharides that consists of disaccharide units that recur itself. The disaccharide unit mainly consists of amino sugar such as ${\rm{N - acetylglucosamine}}$ or ${\rm{N - acetylgalactosamine}}$ along with the uronic sugar or galactose unit attached.

Fundamentals

Keratan is also the example of Glycosaminoglycan in which the sulphate group is present in the amino sugar unit. The amino sugar present in GAGs is ${\rm{N - acetylglucosamine}}$ or ${\rm{N - acetylgalactosamine}}$ .

Those which contains these units, belongs to GAGs.

The ${\rm{N - acetylglucosamine}}$ or ${\rm{N - acetylgalactosamine}}$ structure are as follows:

The Keratan sulfate unit contains the sulphate group attached to the amino sugar group as follows:

In structure B both the disaccharide unit consist of glucose sugar unit or the uronic sugar unit linked by the glycosidic bond.

In Structure E the disaccharide unit consist of glucose unit and the pentose sugar attached by the glycosidic bond.

Both of these structures do not contain any amino group attached in disaccharide.

The structure A contains uronic sugar unit attached with the amino sugar ${\rm{N - acetylglucosamine}}$ .

The structure C contains the uronic sugar unit attached with the amino sugar Keratan sulfate.

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Structure D contains the uronic sugar unit attached with the amino sugar ${\rm{N - acetylglucosamine}}$ .

Ans:

The examples of glycosaminoglycans are structures A, C and D.