Question

Ninhydrin gives a yellow color in paper chromatography with which amino acid?

• A. Tryptophan
• B. Proline
• C. Alanine
• D. Tyrosine

Hint:

Ninhydrin generally reacts with amino acids to form a purple or blue color, but proline is an exception, forming a yellow color due to its unique cyclic structure.

Answer 1

The Correct Option is B

Ninhydrin is commonly used in paper chromatography to detect amino acids. When it reacts with amino acids, it typically produces a purple or blue color. However, there are exceptions, such as proline. Proline, a cyclic amino acid, reacts with ninhydrin to give a yellow color instead of the usual purple or blue color. This unique reaction is due to the structure of proline, which affects the ninhydrin reaction. Therefore, the correct answer is \( \boxed{{B}} \) Proline.