Question

Match the entries in Group I with that in Group II. 
     Group I                                          Group II 
P) Fehling's test                             1) α-Amino acid 
Q) Ninhydrin reaction                    2) Reducing sugar 
R) Biuret reaction                           3) Sulfhydryl group 
S) Nitropusside reaction                4) Peptide linkage 
 

• A. P-1, Q-2, R-3, S-4
• B. P-3, Q-1, R-1, S-4
• C. P-2, Q-1, R-3, S-4
• D. P-4, Q-1, R-2, S-3

Hint:

Each biochemical reaction is specific to a particular compound, such as sugars, amino acids, peptides, or sulfhydryl groups.

Answer 1

The Correct Option is C

Step 1: Understanding the reactions. 
- Fehling's test (P) is used to test for reducing sugars, which reduce Cu\(^{2+}\) to Cu\(^{1+}\) in an alkaline solution. 

- The Ninhydrin reaction (Q) is used to detect amino acids, which react with ninhydrin to form a blue or purple color. 

- The Biuret reaction (R) is used to detect peptide linkages, as it forms a violet color in the presence of proteins or peptides. 

- The Nitropusside reaction (S) is used to detect sulfhydryl groups, typically found in cysteine residues in proteins. 
 

Step 2: Analyzing the options. 
(A) P-1, Q-2, R-3, S-4: Incorrect — This option does not correctly match the reactions with the compounds they detect. 
(B) P-3, Q-1, R-1, S-4: Incorrect — This option does not correctly match the reactions with the compounds they detect. 
(C) P-2, Q-1, R-3, S-4: Correct — This correctly matches each reaction with the compound it detects: - Fehling's test detects reducing sugars (P-2), - Ninhydrin reaction detects α-amino acids (Q-1), - Biuret reaction detects peptide linkages (R-3), - Nitropusside reaction detects sulfhydryl groups (S-4). 
(D) P-4, Q-1, R-2, S-3: Incorrect — This option does not correctly match the reactions with the compounds they detect. 
 

Step 3: Conclusion. 
The correct answer is (C) P-2, Q-1, R-3, S-4, as this correctly matches each reaction with the compound it detects.