Question: amino acid has no net charge?
Answer: The pH at which the net charge of an amino acid is 0 is called the isoelectric point. ... Figure 5 animates the separation of a mixture of glycine, lysine, and aspartic acid at a pH of 6. At this pH the net charge on the aspartic acid is -1, while that on the lysine is +1. There is no net charge on the glycine.