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CBSE Class 12 · BiomoleculesShort Answer

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i) Write one reaction of D-glucose which cannot be explained by its open-chain structure.
ii) What type of linkage is present in nucleic acids?
iii) Give one example each of a water-soluble vitamin and a fat-soluble vitamin.

Solution

(i) Despite 'containing' an aldehyde, glucose gives \textbf{no 2,4-DNP/NaHSO/Schiff reaction} — explained only by the cyclic hemiacetal.
(ii) Nucleotides link through \textbf{phosphodiester bonds} (phosphate bridging C-3′ and C-5′ of successive sugars).
(iii) Water-soluble: \textbf{vitamin C}; fat-soluble: \textbf{vitamin A}.

CBSE Class 12 Board · Subjective

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