Now, which one of these atoms will gain that H atom and be protonated? Well, it's this nitrogen here. So at the physiological PH, this is the nitrogen that can be protonated. And so when this is protonated, we basically gain a positive charge. And that positive charge can be delocalized among this region here. So if this gains an H atom, then what happens is this is delocalized among these two atoms, and there will be a positive charge that is delocalized.