Question

The correct match between Item I and Item II is :

Item I		Item II
(A)	Ester test	(P)	Tyr
(B)	Carbylamine test	(Q)	Asp
(C)	Phthalein dye test	(R)	Ser
		(S)	Lys

• A. (A)\(\rightarrow\)(Q); (B)\(\rightarrow\)(S); (C)\(\rightarrow\)(P)
• B. (A)\(\rightarrow\)(R); (B)\(\rightarrow\)(S); (C)\(\rightarrow\)(Q)
• C. (A)\(\rightarrow\)(R); (B)\(\rightarrow\)(Q); (C)\(\rightarrow\)(P)
• D. (A)\(\rightarrow\)(Q); (B)\(\rightarrow\)(S); (C)\(\rightarrow\)(R)

Hint:

Match each test with the functional group it detects: -COOH (ester test), primary -NH2 (carbylamine test), phenolic -OH (phthalein dye test), then find the amino acid side chain containing it.

Answer 1

The Correct Option is A

Ester test: detects a carboxylic acid group (it forms a fruity-smelling ester with an alcohol and acid catalyst). The amino acid with a free -COOH in its side chain is aspartic acid (Asp), so (A) matches (Q).
Carbylamine test: given by a primary amino group (-NH₂) which forms a foul-smelling isocyanide with CHCl₃ and KOH. Lysine has a primary amino group in its side chain (epsilon-NH₂), so (B) matches (S).
Phthalein dye test: given by phenols, which condense with phthalic anhydride and give a coloured phthalein dye. Tyrosine has a phenolic -OH, so (C) matches (P).
Thus (A)-(Q); (B)-(S); (C)-(P).
Answer: (1) (A)\(\rightarrow\)(Q); (B)\(\rightarrow\)(S); (C)\(\rightarrow\)(P)