AQA A-Level Amino Acids question

Top picture is a reminder of what happens when you have excess haloalkane + NH3 (you keep substituting the Hydrogens on the Ammonia until they have all been replaced by the R- Group of the haloalkane, in this case it was CH3). This keep happening until you get a quaternary amine. The reason it has a positive charge is because in the last reaction, there are no hydrogens to swap, so the Nitrogen atom has to use it's lone pair to accept the final CH3).

The second picture shows that amino acids have similar reaction as they have an amino group which can do the same reaction as above.

Do you understand?