The hexapeptide $P$ has an isoelectric point $(pI)$ of $6.9$. Hexapeptide $Q$ is a variant of $P$ that contains valine instead of glutamate at position $3$. The two peptides are analyzed by polyacrylamide gel electrophoresis at pH $8.0$. Which one of the following statements is CORRECT?
- $P$ will migrate faster than $Q$ towards the anode
- $P$ will migrate faster than $Q$ towards the cathode
- Both $P$ and $Q$ will migrate together
- $Q$ will migrate faster than $P$ towards the anode