Cellulose's hydrogen-bonded structure strengthens plant cell walls

Steps:

• Cellulose consists of β-glucose monomers forming linear polymers.
• β-Glucose units connect via 1-4 glycosidic bonds to create unbranched chains.
• These chains align and bond via hydrogen bonds, forming rigid microfibrils.
• Microfibrils provide tensile strength and support to cell walls.

Why D is correct:

• Hydrogen bonds between unbranched β-glucose chains create a network of parallel microfibrils, giving cell walls mechanical strength and rigidity as per polymer structure principles.

Why the others are wrong:

• A: Glycosidic bonds link glucose units within a single chain, not between adjacent cellulose molecules.
• B: Cellulose forms straight, unbranched chains, unlike branched structures in other polysaccharides like glycogen.
• C: 1-4 glycosidic bonds build individual chains but do not link chains together for structural reinforcement.

Final answer: D