Add the following lines to you .bashrc file in you home directory.

PATH="$PATH:/home/threader/kinetic/bin/qmake"
export PATH

Chances are lines like above already exist, so you add ":/home/threader/kinetic/bin/qmake" to the end of the string.

If you're not using the default Bash shell (which I doubt), find .cshrc, etc.

This is not Qt issue.

Google .bashrc