How is an amino acid different from each other?

Amino acids have the structure 

COOH-C(H)(R)-NH2 

The differences are in the R-groups where different functional groups in the r-groups of each amino acid causes them to have different properties (ie. some are acidic and some are basic)

Some of her  assignments would be creation of drugs. she is a medical chemist after all so she'd need to have the necessary knowledge to make medicine which can later be sold in a pharmacy