Match the LIST-I with LIST-II
| LIST-I: Biomolecules | LIST-II: Characteristic features | ||
| A. | Curdling of milk | I. | Pentose sugar and nitrogenous base |
| B. | Cellulose | II. | Hydrogen bonding |
| C. | α - Helix | III. | Denaturation of protein |
| D. | Nucleoside | IV. | β -links |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → A-III, B-IV, C-II, D-I
Each term in List-I belongs to one class of biomolecules, and the matching feature follows from its structure:
(A) Curdling of milk — This matches (III) Denaturation of protein. Lactic acid formed by bacteria lowers the pH, the milk proteins lose their secondary and tertiary structure and coagulate, while the primary structure stays intact.
(B) Cellulose — This matches (IV) β -links. Cellulose is a straight chain polysaccharide of β-D-glucose units joined by C1–C4 glycosidic links; humans lack the enzyme to break these links.
(C) α - Helix — This matches (II) Hydrogen bonding. The polypeptide chain coils into a right-handed helix held by hydrogen bonds between the –NH group of one amino acid unit and the C=O group of another further along the chain.
(D) Nucleoside — This matches (I) Pentose sugar and nitrogenous base. A nucleoside is a base attached to the 1′ carbon of the pentose sugar; adding a phosphate group at 5′ gives a nucleotide.
Shortcut: The pair (C)–(II) appears only in Option (1).