The fully folded structure of a functional protein composed of a single polypeptide chain is referred to as the structure. primary secondary quaternary tertiary

The answer is Tertiary Structure which means the three dimensional or full folded structure of a functional protein which composed of a single polypeptide chain. A primary structure is a sequences of amino acids in polypeptide chain. A secondary structure is ordered arrangement of the amino acid in localize regions of polypeptide molecule. A quaternary structure is only used to describe proteins which composed of multiply sub units.

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