Doubt in bimolecules

Please tell whatvis the procedure to do these type of questions.

Please also do this for basic and neutral medium

Help @Shwetanshu_2018 @Samarth_2020

in basic medium the basic sites are unaffected, whereas the -COOH group loses its oxygen and become -COO minus. In neutral medium everything is intact.

In these type of questions, I went to remember all the structures of amino acids, but it is totally waste of time. The structures are given in the options, mark the basic and acid sites. Now see what kind of medium is it and accordingly change the basic or acidic sites.

My doubt here is why is the 3 N not basic. Please elaborate

I didn't understand. What is your 3N?

Becz lone pair are delocalised in 3rd nitrogen

Okay, he was talking about third nitrogen. Yes, it is involved in resonance.

Can you please explain what happens if it is involved in resonance. Like didn't understand your reason for excluding that N due to resonance

If the lone pair on nitrogen is involved in resonance, then the lone pair is not available for the acids to react with it, so it is unreactive.

Thanks @Samarth_2020