# Biuret test is not given by

$\begin {array} {1 1} (A)\;Proteins & \quad (B)\;Carbohydrates \\ (C)\;Polypeptides & \quad (D)\;Urea \end {array}$

Biuret Test
The Biuret Reagent is made of sodium hydroxide and copper sulfate. The blue reagent turns violet in the presence of proteins, and changes to pink when combined with short-chain polypeptides.
Carbohydrates does not contain $CO-NH$ group so it doesn’t give biuret
Ans : (B)