An amino acid must have which of the following properties in order to be incorporated into a polypeptide?

Peptide-Bond Formation is the linking of two amino acids is accompanied ... with an α-amino group at one end and an α-carboxyl group at the other.

Proteins are combination of amino acids. When the adjoining amino acid residues are bonded by a linear chain of adjoining carboxyl and amino groups a polypeptide is formed.

Hence for the formation of peptide bond two amino acid groups are required one end is combined with alpha amino group and the other end is combined with alpha carboxyl group

Note: Peptide bonds are linked together by short chain of amino acids

Amino acids are the broken down substances which when digested provide energy to the human body for metabolism