Question

The amino acid isoleucine has pKa values of 2.32 (–COOH) and 9.76 (–NH3+). What is the predominant form of the amino acid at pH = 6.0? Fill in any missing hydrogen atoms and/or charges on the provided structure to adjust the structure to reflect a pH of 6.0.

Answer 1

Answer:

PI = 6.04

In the attached figure are the missing hydrogen atoms

Explanation:

Given both pk, the isoelectric point will be equal to:

PI = (1/2)*(pka + pka2), where pka = 2.32 and pka2 = 9.76

PI = (1/2)*(2.32 + 9.76) = 6.04