Q.33 Which of the following statements are TRUE for cellulose?
(A) Cellulose serves a structural role
(B) Cellulose is a branched polysaccharide
(C) Cellulose is a homopolysaccharide composed of (α1→4) linked D-glucose
units
(D) Cellulose is a homopolysaccharide composed of (β1→4) linked D–glucose units
Cellulose is a key structural polysaccharide in plant cell walls, and options (A) and (D) correctly describe its properties. This analysis evaluates each statement for accuracy, relevant to CSIR NET Life Sciences preparation.
Option Analysis
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(A) True: Cellulose provides tensile strength to plant cell walls through hydrogen-bonded microfibrils, enabling structural support against turgor pressure.
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(B) False: Cellulose consists of linear, unbranched chains of glucose units, unlike branched polysaccharides such as glycogen.
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(C) False: While cellulose is a homopolysaccharide of D-glucose, the linkages are β1→4, not α1→4 (which characterizes starch like amylose).
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(D) True: Cellulose forms via β1→4 glycosidic bonds between D-glucose units, creating straight chains that align parallel for microfibril formation.
Correct answer: (A) and (D).
Cellulose structure plays a vital role in plant biology, serving as the primary component of cell walls with its unbranched chains of β1→4 linked D-glucose units. For CSIR NET aspirants, understanding cellulose’s homopolysaccharide nature and structural role is essential for questions on polysaccharides.
Key Properties
Cellulose excels in providing rigidity due to extensive hydrogen bonding between parallel chains.
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Linear polymer of thousands of D-glucose monomers.
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β1→4 glycosidic bonds invert every second glucose, preventing coiling unlike α-linked starch.
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Forms tough microfibrils embedded in a hemicellulose matrix for plant support.
Common Misconceptions
Many confuse cellulose with starch; starch uses α1→4 linkages for energy storage, while cellulose’s β linkages ensure indigestibility in humans. Branched structures apply to amylopectin or glycogen, not cellulose.
CSIR NET Relevance
Questions like “Which statements are TRUE for cellulose?” test linkage specificity and function. Focus on β1→4 D-glucose for homopolysaccharide identification.
