Question

a long chain of molecules linked by amino acids binding together is a

Explanation:

In Biology (a subfield of Natural Science), a long chain of amino acids linked together forms a polypeptide (or a protein, as polypeptides fold into proteins). Amino acids are linked by peptide bonds during protein synthesis, and a long chain of these linked amino acids is a polypeptide (the primary structure of a protein).

Answer:

polypeptide (or protein)