When the power supply is switched on, some amino acids may stay in the same place instead of moving. Suggest an explanation for this observation.
The amino acid glycine has the formula $\text{H}_2\text{NCH}_2\text{CO}_2\text{H}$. Identify the species present on the filter paper if glycine travels to the left (positive) end of the filter paper.
A different electrophoresis produced the result below. What deductions can be made about the relative sizes of, and charges on, amino acid species A, B and C?
After such a partial hydrolysis, these tripeptides were obtained from a polypeptide: ala-gly-asp, gly-ala-gly, lys-val-ser, ser-ala-gly, val-ser-ala. If the N-terminal amino acid is lysine (lys), suggest the amino acid sequence of the shortest polypeptide that could produce the tripeptides above.
Among the tripeptides in (i), which one has the lowest $M_r$?
Select one amino acid from those listed in the table that has an ionic side-chain at pH $8$.