The \(pK_{a_1}\) and \(pK_{a_2}\)of an amino acid are 2.3 and 9.7 respectively. The isoelectric point of the amino acid :

6.0

The correct answer is option 3. 6.0.

The isoelectric point (pI) of an amino acid is calculated as the average of the pKa values of the carboxyl and amino groups. Given the pKa1 (carboxyl group) is 2.3 and pKa2 (amino group) is 9.7, the isoelectric point can be calculated as follows:

\( \text{pI} = \frac{\text{pKa1} + \text{pKa2}}{2} \)

Substituting the given values:

\( \text{pI} = \frac{2.3 + 9.7}{2} = \frac{12.0}{2} = 6.0 \)

So, the isoelectric point of the amino acid is 6.0.