Citation:
The quaternary structure of a protein refers to the way in which multiple polypeptide chains (proteins) come together and interact. It's the highest level of organization in a protein.
A long chain of amino acids linked by peptide bonds, which forms part of a protein's structure.
The three-dimensional shape that allows an entire protein or polypeptide chain to fold upon itself.
Protein Folding: The process by which a protein takes on its functional shape or conformation.