Both of these amino acids are non-polar and aliphatic and have a four-carbon side chain emerging from the basic amino acid structure. The skeletal structure of leucine is shown below.

Amino acids have a basic backbone made of an amino group and a carboxyl group, and differ in their side-chains. Skip to content. Menu. ... which come together to form a 3D structure.

Peptides are chains of amino acids, simple organic compounds that form the building blocks of proteins. Inside the body's cells, amino acids are used for growth, maintenance and repair.