Question

Draw the predominant form for glutamate in a solution with the following pH: 3, 6, 11

Answer 1

Draw the predominant form for glutamate in a solution with the following pH: 3, 6, 11

pKa values of all ionizable groups in Glutamic acid shown here.

At or above those pKa i.e. pH values that particular proton(s) are ionized in the aqueous medium.

At pH = 3, main –COOH (pKa =2.2) will ionize in the solution and hence the form-1.

At pH =6, both –COOH (pKa = 2.2 and 4.2) will ionize in the solution and hence the form-2

At pH = 11, both –COOH as well as –NH3(pKa =9.7) will ionize in the solution and hence the form-3.

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