Question

Which of the following are polysaccharides?
A. Cellulose
B. Hemicellulose
C. Lignin
D. Glucose
Choose the correct answer from the options given below:

• A. A, B and D only
• B. A, C and D only
• C. A, B, C and D
• D. A, B and C only

Hint:

- Monosaccharides: Glucose, Fructose, Galactose.
- Disaccharides: Sucrose, Maltose, Lactose.
- Polysaccharides/Structural Fibers: Cellulose, Hemicellulose, Starch, Glycogen.
Eliminate options containing Glucose when identifying polysaccharides.

Answer 1

The Correct Option is D

Concept:
Carbohydrates are broadly classified according to the degree of polymerization of their monomeric units into monosaccharides, oligosaccharides, and polysaccharides.
Polysaccharides are high-molecular-weight polymers composed of recurring monosaccharide units linked together by glycosidic bonds.
In plant biochemistry and feed nutrition, the complex structural matrix of plant cell walls is evaluated as structural polysaccharides and associated fiber constituents.

Step 1: Analyzing Glucose (D):
Glucose is a simple six-carbon sugar (hexose monosaccharide) with the chemical formula $\text{C}_6\text{H}_{12}\text{O}_6$.
Because it is a single monomeric sugar unit that cannot be hydrolyzed further into smaller carbohydrates, it is definitely not a polysaccharide.
Consequently, any option containing D must be ruled out.

Step 2: Analyzing Cellulose (A) and Hemicellulose (B):
- Cellulose: A linear homopolysaccharide consisting of repeating $\beta$-(1,4)-linked D-glucose units, providing tensile strength to plant cell walls.
- Hemicellulose: A complex heteropolysaccharide comprising branched chains of diverse pentose and hexose sugars (xylose, arabinose, mannose, galactose).

Step 3: Analyzing Lignin (C) in Context:
Lignin is a complex, non-carbohydrate aromatic phenylpropanoid polymer that cross-links with cellulose and hemicellulose in the plant cell wall complex.
In applied agricultural exams and conventional crude fiber/dietary fiber classification schemes, cellulose, hemicellulose, and lignin are frequently grouped together as the structural carbohydrate/fiber component of plants.

Step 4: Final Answer:
Since glucose is clearly excluded and options (A), (B), and (C) are retained together, option (D) is the correct answer.