Respuesta :

Two amino acids are linked together by the formation of a peptide bond. Amino acids joined by a series of peptide bonds to make a peptide chain. Thus , a protein molecule is a polypeptide chain composed of many amino acid residues.

Answer : The molecules link together to form protein is, Amino acid.

Explanation :

Amino acid : It is defined as the acid which contains two functional groups that are carboxylic group, [tex]-COOH[/tex] and ammine group, [tex]-NH_2[/tex].

When the two or more amino acids combine together with the help of peptide bond, they produces polypeptide chain and form protein.  The bond present between the two amino acid is called a peptide bond.

Hence, the molecules link together to form protein is, Amino acid.