Zwitter ion is formed by

What does hemoglobin in red blood cells primarily contain?

The structure of a peptide is given below. If the absolute values of the net charge of the peptide at $pH = 2$,$pH = 6$,and $pH = 11$ are $|z_1|$,$|z_2|$,and $|z_3|$,respectively,then what is $|z_1| + |z_2| + |z_3|$?

Identify the basic amino acid from the following.

Identify the pair of reactants that upon reaction,with elimination of $HCl$,will give rise to the dipeptide $Gly-Ala$.

When proteins are heated with concentrated $HNO_3$,a yellow color is obtained. What is this test called?