1. Context

A protein is a biological macromolecule obtained by the copolymerization of amino acids, linked by peptide bonds. There are around twenty different amino acids in biological proteins. The nature of the amino acids present in a protein, and the way they are linked, are responsible for its final structure, as well as its properties and functional capacities.

Depending on the number of amino acids, a distinction is made between :

• Peptides: less than 50 linked amino acids;

• proteins: more than 50 amino acids (some are very large molecules, or macromolecules).

Within a protein, amino acids are linked by peptide bonds. These are amide bonds, formed by the elimination of a water molecule between the C-terminal function of one amino acid and the N-terminal...