Given the pKa values of an amino acid with ionizable R groups as 2.1, 9.3, and 10.5, order them from smallest to largest.

Using the four-step process, calculate the isoelectric point for an amino acid with pKa values of 3.1, 8.2, and 11.0.

If the calculated isoelectric point for an amino acid is 5.5, but the known value is 5.7, what might be the reason for the discrepancy?

What is the main difference in the calculation of pI for amino acids with ionizable R groups?