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Why doesn't cellulose react with iodine to produce a blue color?
It lacks the helical structure necessary for iodine complexation.
It contains fructose units instead of glucose.
It is a branched polymer and cannot interact with iodine.
It is insoluble in water, preventing the reaction with iodine.
Which structural characteristic of cellulose prevents it from forming a blue color with iodine?
α-1,4-glycosidic linkages
β-1,4-glycosidic linkages
Presence of fructose units
Branched polymer structure
Iodine forms a blue color complex with starch but not with cellulose. This difference is primarily due to:
The presence of branching in cellulose.
The higher molecular weight of cellulose.
Difference in glycosidic linkages and resulting structural conformations.
The different monomer composition of cellulose and starch.
Which of the following statements are incorrect?
I. Left end of a polysaccharide is called non-reducing end while right end is called reducing end
II. Starch and glycogen are branched molecules
III. Starch and glycogen are the reserve food materials of plants and animals, respectively
IV. Starch can hold iodine molecules in its helical secondary structure but cellulose being non-helical, cannot hold iodine
I and II
II and III
I and IV
III and IV
Answer briefly
I. Which colour glycogen gives on its reaction with iodine solution?
II. What is satellite DNA?
III. Name three components of a nucleotide molecule
Correct option will all answers is
Reddish-brown; Highly repetitive DNA; Nitrogenous base, pentose sugar, phosphate group
Blue-black; Non-repetitive DNA; Amino acid, hexose sugar, phosphate group
Yellow; Moderately repetitive DNA; Nitrogenous base, triose sugar, sulphate group
Violet; Unique DNA; Amino acid, pentose sugar, phosphate group
