Which is not a polysaccharide?A. SucroseB. StarchC. GlycogenD. Cellulose

To determine which option is not a polysaccharide, let's first define what polysaccharides are and then examine each option.

Definition of Polysaccharides:
Polysaccharides are carbohydrates that are made up of long chains of monosaccharide units (sugars) linked together by glycosidic bonds. They serve various functions, including energy storage and structural support.

Analyzing the Options:
A. Sucrose:

Sucrose is a disaccharide, composed of two monosaccharides: glucose and fructose. It is commonly known as table sugar and is not a polysaccharide.
B. Starch:

Starch is a polysaccharide made up of many glucose units. It is a primary energy storage molecule in plants.
C. Glycogen:

Glycogen is also a polysaccharide, consisting of many glucose units. It serves as the primary energy storage form in animals.
D. Cellulose:

Cellulose is a polysaccharide made up of long chains of glucose units. It is a key structural component of plant cell walls.
Conclusion:
The only option that is not a polysaccharide is A. Sucrose.

Thus, the answer is: A. Sucrose