Question

Amino acid can be isolated at its isoelectric point.
If true enter 1, else enter 0.

Answer 1

The amino acids that comprise of protein can be either positively or negatively charged overall due to the terminal amine $-N{H}_2$ and carboxyl $(-COOH)$ groups and the groups on the side chain. It is positively charged at low $pH$ and negatively charged at high $pH$.
The intermediate $pH$ at which a amino acid molecule has a net charge of zero is called the isoelectric point of that amino acid. In general, the net charge on it, either positive or negative, can interact with water molecules. As a result, amino acid is the least soluble when the $pH$ of the solution is at its isoelectric point and so, amino acids can be isolated at its isoelectric point.