Homework SourseWhich of the following statements about the polysaccharide c
Which of the following statements about the polysaccharide cellulose is incorrect?
| Cellulose is used to build houses and make cardboard. |
| The glucose monomers in cellulose arrange in a helical conformation. |
| Microorganisms breakdown cellulose for some grazing animals by producing an enzyme called cellulase. |
| The human body lacks the enzyme to breakdown the -1,4 glycosidic link in cellulose. |
Solution
Ans. Correct option- B. The glucose monomers in cellulose arrange in a helical conformation. This statement is false.
Cellulose is a linear, unbranched homopolymer of -D-glucose, it does NOT take up a helical conformation. The helical conformation is a characteristic of amylose in starch.
# Statement A- True. Being rigid and strong, cellulose can be used as structural material like house (say, using logs, bamboo, etc.) and cardboard, etc.
# Statement C- True. Cellulose is a linear, unbranched homopolymer of -D-glucose linked together by (14) glycosidic bond. Animals produce only -glycosidase but not -glycosidase (an enzyme that hydrolyzes cellulose), thus are unable to digest cellulose. Cellulose is metabolized only by some -glycosidase producing microbes (some bacteria, protozoa) and some animals (ex- termites, ruminants and other herbivorous) that harbor such microbes in their gastrointestinal tract.
# Statement D- True. As mentioned in #C, humans and all animals lack b-galactosidase enzyme needed to hydrolyse b-1,4-glycosic bonds in cellulose.
