The acid showing salt-like character in aqueous solution is

The secondary structure of protein refers to .......

The secondary structure of protein is determined by

When dilute $H_2SO_4$ is added to an alkaline solution of protein,a violet color is obtained. What is this test called?

Which of the following amino acids contains a heterocyclic ring in its side chain $(R)$ group?

Assertion : At isoelectric point,the amino acid does not migrate under the influence of an electric field.
Reason : At isoelectric point,amino acid exists as a zwitterion.