Classifying glucose polymers by structure and function

Steps:

• Examine diagram P: linear, unbranched chains indicate cellulose for plant cell walls.
• Examine diagram Q: highly branched structure indicates glycogen for animal energy storage.
• Examine label R: describes compact, mobilizable form for quick glucose release, matching energy storage.
• Match to options: only B aligns P as cellulose, Q as glycogen, and R as energy storage.

Why B is correct:

• Glycogen's branched α-1,6 linkages allow rapid enzymatic breakdown for energy, unlike linear cellulose's β-1,4 bonds for rigidity.

Why the others are wrong:

• A: Amylopectin is plant starch (branched), not animal glycogen; R mismatches cellulose's role.
• C: Swaps P and Q; glycogen is branched (not linear like cellulose), and R fits glycogen, not cellulose.
• D: Swaps P and Q; R's storage function suits glycogen, not structural cellulose.

Final answer: B