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 structures are examples of glycosaminoglycans?
The Correct Answer and Explanation is :
Glycosaminoglycans (GAGs) Overview
GAGs are long, unbranched polysaccharides consisting of repeating disaccharide units. These disaccharide units generally contain:
- A Hexosamine – either N-acetylglucosamine or N-acetylgalactosamine.
- An Acidic Sugar – usually glucuronic acid or iduronic acid.
GAGs are negatively charged due to their sulfate or carboxyl groups, making them hydrophilic and essential in extracellular matrices, cartilage, and connective tissues.
Common GAGs
- Hyaluronic Acid – Composed of glucuronic acid and N-acetylglucosamine.
- Chondroitin Sulfate – Contains glucuronic acid and N-acetylgalactosamine sulfate.
- Dermatan Sulfate – Composed of iduronic acid and N-acetylgalactosamine sulfate.
- Heparan Sulfate – Made of glucuronic/iduronic acid and N-acetylglucosamine sulfate.
- Keratan Sulfate – Unique as it lacks uronic acid and contains galactose and N-acetylglucosamine sulfate.
Identifying GAGs from the Structures
If the provided image contains molecules with:
- Repeating disaccharides
- A hexosamine (N-acetylglucosamine or N-acetylgalactosamine)
- An acidic sugar (glucuronic acid, iduronic acid, or sulfate modifications)
Then those structures are glycosaminoglycans.