(a)[2]
Consult the Data Booklet to sketch the structure of the dipeptide val-lys. The peptide bond should be presented in displayed form.
(b)[5]
The isoelectric point is the pH at which an amino acid is present as a zwitterion. Valine has an isoelectric point of 6.0, whereas lysine has one of 9.8. A mixture containing the dipeptide, val-lys, and its two component amino acids, valine and lysine, was separated by electrophoresis in a buffer at pH 6.0. Draw and label three spots on the electrophoresis paper diagram to show the probable position of each of these three species after electrophoresis. Explain your answer.