Answer:-

1. The unique characteristic responsible for this phenomenon is the zwitterion structure of α-amino acids.
2. α-Amino acid molecules encompass both an acidic carboxyl group (-COOH) and a basic amino group (-NH₂).
3. When a proton is transferred from the acidic group to the basic amino group within the amino acid, it results in the formation of a salt, which takes the form of a dipolar ion known as a zwitterion.

As a consequence, α-amino acids exhibit notably high melting points in comparison to amines or carboxylic acids of similar molecular mass.