Question 13:
Match List I with List II:
| List I Functional Group |
List II Description |
|---|---|
| A. Hydroxyl | I. DNA |
| B. Carboxyl | II. Proteins |
| C. Amino | III. Polar |
| D. Phosphate | IV. Fatty acids |
Choose the correct answer from the options given below:
The correct matching for the functional groups is option (A): Hydroxyl (Polar), Carboxyl (Fatty acids), Amino (Proteins), Phosphate (DNA).
Correct Answer: (A)
Option (A) correctly pairs each functional group with its primary biological description: Hydroxyl (-OH) as polar due to H-bonding; Carboxyl (-COOH) in fatty acids; Amino (-NH₂) in proteins (amino acids); Phosphate (-PO₄) backbone of DNA.
Options Analysis
| Option | Matching | Explanation |
|---|---|---|
| (A) | A-III, B-IV, C-II, D-I | Correct. Hydroxyl: polar; Carboxyl: fatty acids; Amino: proteins; Phosphate: DNA backbone. |
| (B) | A-I, B-II, C-III, D-IV | Wrong. Hydroxyl ≠ DNA (that’s phosphate); Carboxyl ≠ proteins (that’s amino). |
| (C) | A-II, B-IV, C-I, D-III | Wrong. Hydroxyl ≠ proteins; Amino ≠ DNA. |
| (D) | A-IV, B-III, C-I, D-II | Wrong. Hydroxyl ≠ fatty acids (those have carboxyl). |
Biological Roles
Hydroxyl groups enable polarity in alcohols/sugars for solubility. Carboxyl provides acidity in fatty acids/lipids. Amino forms peptide bonds in proteins. Phosphate links nucleotides in DNA. This matching tests core biochemistry knowledge for exams.
