Answer;
Quaternary structure
Step-by-step explanation;
-Amino acids link together end-to-end forming the primary structure of proteins.
-Chemical properties of amino acid groups within a sequence interact with one another in secondary protein structure resulting in hydrogen bonding and chain folding.
-Intramolecular bonding of polypeptide chains produces numerous alpha helices and beta sheets.
-Globular and fibrous shapes are created with tertiary structure of proteins caused by further folding due to disulfide bridges, hydrophobicity and Van der Waals forces.
-More than one globular or fibrous protein subunit now interact to produce quaternary structure, which results from ionic, hydrophilic, and hydrophobic interactions.