In a protein molecule, the number of amino acid molecules may be as few as 5 500 50 5,000

50

Explanation:

Polymer is a macro molecule formed by combination of small units called as monomers by joining as such or by liberation of small molecules.

Proteins are biological polymers formed by combination of small units called as amino acids which contain elements such as H,N,O,C etc and are bonded to each other through a peptide bond.

Proteins are polymers made up of amino acids ranging from 50 to 5000.