(a)[2]
Use the Data Booklet to help you draw the structure of the dipeptide glu-cys.
(b)[3]
Suggest the identities of the species responsible for spots E, F and G. Explain your reasons.
Chemistry 9701 · AS & A Level · States of matter
States of matter — practice question
The isoelectric point is the pH at which an amino acid is present as a zwitterion. Glutamic acid has an isoelectric point of 3.2 and cysteine has an isoelectric point of 5.0. A mixture containing the dipeptide glu-cys and its two component amino acids, glutamic acid and cysteine, was separated by electrophoresis in a buffer at pH 5.2. The results are shown.