Tiingutiingu
Sign up

Isoelectric point (pI) of amino acids (pI = (pKa1 + pKa2)/2 for neutral amino acids (α-COOH and α-NH3+))

jee-mainjee-advancedneet-ug

pI = (pKa1 + pKa2)/2 for neutral amino acids (α-COOH and α-NH3+)

What each symbol means

SymbolWhat it stands for
pKa1, pKa2The two pKa values bracketing the zwitterion (commonly carboxyl and amino for neutral R)

When to use this

For amino acids with ionizable side chains, pI is average of the two pKa values of the protonation states that bracket the neutral zwitterion (JEE uses standard recipes per NCERT level).