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CBSE Class 12 · 2016 · Delhi · BiomoleculesShort Answer

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i) Write the names of the two monosaccharides obtained on hydrolysis of lactose.
ii) Why can vitamin C not be stored in our body?
iii) What is the difference between a nucleoside and a nucleotide?

Solution

(i) Lactose + HO → \textbf{D-glucose + D-galactose}.
(ii) Vitamin C is \textbf{water-soluble}: any excess passes into urine, so the body keeps no store — it must come regularly in food.
(iii) \textbf{Nucleoside}: base–sugar unit only. \textbf{Nucleotide}: base–sugar–\textbf{phosphate}; nucleotides are the repeating units of nucleic acids.

CBSE Class 12 Board · 2016 · Delhi · Subjective

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