Question

multiple-choice question quaternary structure involves interactions between multiple polypeptides is primarily caused by ionic bonding is the sequence of amino acids is found in all proteins

Explanation:

• For "involves interactions between multiple polypeptides": The quaternary structure of a protein is defined as the arrangement of multiple polypeptide chains (subunits) in a multi - subunit protein. So this statement is correct.
• For "is primarily caused by ionic bonding": The quaternary structure is stabilized by various interactions like hydrogen bonds, hydrophobic interactions, ionic bonds, and disulfide bridges, and it is not primarily caused by ionic bonding. So this statement is incorrect.
• For "is the sequence of amino acids": The sequence of amino acids in a polypeptide chain is the primary structure of a protein, not the quaternary structure. So this statement is incorrect.
• For "is found in all proteins": Not all proteins have a quaternary structure. Some proteins are composed of a single polypeptide chain (monomeric proteins) and thus do not have a quaternary structure. So this statement is incorrect.

Answer:

The correct option is: involves interactions between multiple polypeptides