Question
Question: Proteins when heated with conc. \(\mathrm { HNO } _ { 3 }\) give a yellow colour. This is...
Proteins when heated with conc. HNO3 give a yellow colour. This is
A
Oxidising test
B
Xanthoprotic test
C
Hoppe's test
D
Acid-base test
Answer
Xanthoprotic test
Explanation
Solution
Protein + conc. HNO3 → Yellow colour
[This test is given by a protein which consists of α-amino acids containing a benzene ring such as tyrosine, phenylalanine etc. The yellow colour is due to nitration of benzene ring.]