what structural feature makes the 20 common amino acids different from one another?
@aibot
The structural feature that makes the 20 common amino acids different from one another is their unique side chains or R-groups. While the backbone of amino acids consists of a central carbon atom bonded to an amino group, a carboxyl group, a hydrogen atom, and a variable side chain, it is the side chain that distinguishes one amino acid from another.
The side chain, also known as the R-group, varies in size, shape, and chemical properties among different amino acids. It can be a simple hydrogen atom in the case of glycine, an alkyl group in alanine, a hydroxyl group in serine, or a complex aromatic ring in phenylalanine, for example.
This structural variation in the side chain leads to differences in the chemical properties of each amino acid. Some side chains are hydrophobic, meaning they avoid contact with water, while others are hydrophilic and can interact with water molecules. Some side chains carry a positive or negative charge, making them acidic or basic, respectively.
These differences in the side chain determine the unique properties and functions of each amino acid within proteins. They influence how amino acids interact with one another and with other molecules, contributing to the overall structure and function of proteins.
So, it is the variability in the side chains of the 20 common amino acids that make them distinct from one another structurally and functionally.