Question

Which part of the amino acid helps identify features that differentiate one amino acid from another

Answer 1

The part of the amino acid which helps to identify features that differentiate one amino acid from another is the SIDE CHAIN OF EACH AMINO ACID.
Amino acids are made up of five basic parts, these are:
1. A central carbon atom
2. A hydrogen atom
3. An amino group
4. A carboxyl group and 
5. A R group, also known as a side chain.
The side chain distinguishes one amino acid from the other; different amino acids have different side chains.