Concept #1: Isoelectric Focusing
Practice: At some point during isoelectric focusing, proteins stop moving through the gel because:
Practice: Electrophoretic separation at pH 6 of a sample mixture with Peptide #1 (MW 100) Peptide #2 (MW 200) and Peptide #3 (MW 400) would result in which of the following? (Note: the pI of each peptide occurs at pH 6).
Practice: Mark the approximate final position of the following tripeptide on the isoelectric focusing gel: Glu-Met-Asp.
Hint: calculate the isoelectric point of the peptide.