What is the difference between primary structure of a protein and a polypeptide?
Primary structure = the amino acid sequence of the peptide chains. so unless the polypeptide is all the same amino acid there is no difference Tertiary structure = three-dimensional structure of a single protein molecule; a spatial arrangement of the secondary structures. It also describes the completely folded and compacted polypeptide chain. Quaternary structure = complex of several protein molecules or polypeptide chains, usually called protein subunits in this context, which function as part of the larger assembly or protein complex.
