Cellulose differs from starch in that:

• A. Cellulose is a storage polysaccharide in animals, while starch is found in plants.
• B. Cellulose is easily digested by humans, while starch is not.
• C. Cellulose has β(1→4) glycosidic bonds, while starch has α(1→4) glycosidic bonds.
• D. Cellulose is composed of fructose monomers, while starch is composed of glucose monomers.

Answer: (C)

Verified step by step guidance

1. Understand the structural difference between cellulose and starch: Both are polysaccharides, but they differ in the type of glycosidic bonds connecting their monomers. Cellulose has β(1→4) glycosidic bonds, while starch has α(1→4) glycosidic bonds.
2. Recognize the biological roles of cellulose and starch: Cellulose is a structural polysaccharide found in the cell walls of plants, providing rigidity and support. Starch, on the other hand, is a storage polysaccharide in plants, used to store energy.
3. Clarify the digestibility in humans: Humans cannot easily digest cellulose because we lack the enzyme cellulase to break β(1→4) glycosidic bonds. Starch, however, is easily digested by humans using enzymes like amylase, which break α(1→4) glycosidic bonds.
4. Identify the monomers: Both cellulose and starch are composed of glucose monomers, not fructose. The difference lies in the orientation of the glycosidic bonds between these glucose units.
5. Summarize the key distinction: The correct answer is based on the type of glycosidic bonds—β(1→4) in cellulose versus α(1→4) in starch. This structural difference is crucial for their function and digestibility.