All of the following are polysaccharides except _.
Multiple Choice
glycogen in liver and muscle
a cell’s glycocalyx
prostaglandins in inflammation
cellulose in certain cell walls
agar used to make solid culture media
The Correct Answer and Explanation is :
The correct answer is prostaglandins in inflammation.
Explanation:
Polysaccharides are complex carbohydrates composed of long chains of monosaccharide units linked by glycosidic bonds. They serve various functions in organisms, including energy storage and structural support. Let’s review each option:
- Glycogen in liver and muscle:
Glycogen is a polysaccharide made up of glucose units linked together in branched chains. It serves as a primary energy storage molecule in animals, particularly in the liver and muscles. When the body needs energy, glycogen can be broken down into glucose molecules through hydrolysis. - A cell’s glycocalyx:
The glycocalyx refers to a layer of glycoproteins and glycolipids that cover the surface of many cells. The carbohydrate portions of these molecules, including those attached to proteins or lipids, are considered polysaccharides. The glycocalyx plays a role in cell recognition, communication, and protection. - Prostaglandins in inflammation:
Prostaglandins are not polysaccharides; they are lipids. These molecules are derived from fatty acids and play important roles in processes like inflammation, blood clotting, and regulation of blood flow. Prostaglandins are not made up of long chains of sugar molecules and thus do not qualify as polysaccharides. - Cellulose in certain cell walls:
Cellulose is a polysaccharide composed of glucose units linked by beta-glycosidic bonds. It is a major structural component in the cell walls of plants. Cellulose provides rigidity and strength to the plant structure. - Agar used to make solid culture media:
Agar is a polysaccharide extracted from seaweed. It is commonly used as a medium in laboratories to support the growth of microorganisms. Agar is a complex carbohydrate that forms a gel-like substance when dissolved in boiling water and cooled.
Therefore, the only molecule in the list that is not a polysaccharide is prostaglandins, making it the correct answer.