Question

Match the LIST-I with LIST-II.

Choose the correct answer from the options given below:

• A. A-IV, B-II, C-I, D-III
• B. A-IV, B-I, C-II, D-III
• C. A-III, B-II, C-I, D-IV
• D. A-IV, B-I, C-III, D-II

Hint:

Identify the functional groups: Glutamine has an amide, Lysine has a primary amine, Tyrosine has a phenol, and Serine has an alcohol. Match these to their standard qualitative tests.

Answer 1

The Correct Option is B

To solve this matching problem, we need to identify the specific functional groups present in the side chains of the given amino acids and match them with the chemical tests that identify those functional groups.

1. Glutamine (A): The side chain of glutamine contains an amide group ($-CONH_2$). The Hoffman bromamide degradation is a specific reaction for primary amides, where they react with $Br_2$ and $KOH$ to form a primary amine with one fewer carbon atom. Thus, A matches with IV.

2. Lysine (B): Lysine has a side chain containing a primary aliphatic amino group ($-NH_2$ at the epsilon position). Hinsberg's test (using benzene sulfonyl chloride) is used to distinguish between primary, secondary, and tertiary amines. A primary amine reacts to form a sulfonamide that is soluble in alkali. Thus, B matches with I.

3. Tyrosine (C): Tyrosine contains a phenolic hydroxyl group ($-C_6H_4OH$) in its side chain. Phenols react with neutral ferric chloride ($FeCl_3$) solution to produce characteristic colored complexes (usually violet, blue, or green). Thus, C matches with II.

4. Serine (D): Serine contains an aliphatic alcoholic hydroxyl group ($-CH_2OH$) in its side chain. The Ceric ammonium nitrate (CAN) test is a standard test for the detection of the alcohol functional group, resulting in a color change from yellow to red. Thus, D matches with III.

Correct matching: A-IV, B-I, C-II, D-III.