Practice: What is the pI of His?

Concept #1: Calculating Isoelectric Point Of Amino Acids With Ionizable R-Groups

Practice: What is the pI of His?

Practice: Electrophoresis separates molecules by migration through a gel only if they have a net charge. How do you expect an amino acid to migrate during electrophoresis when the pH = pI?

Practice: Draw Glu and calculate its isoelectric point. pK_{a1} = 9.67. pK_{a2} = 2.19. pK_{R} = 4.25.

Practice: Calculate Cys’s pI.

Practice: Calculate the pI of Arg. pK_{a1} = 9. pK_{a2} = 2.2. pK_{R} = 12.5.

Practice: Calculate the pI of Asp.