BIOMOLECULES AND ENZYMES

Detailed explanation-1: -The quaternary structure is also stabilized by the non-covalent interactions and disulfide bonds as in the tertiary structure, where more than one polypeptide is held together to form a single functional unit called multimer.

Detailed explanation-2: -Hemoglobin. Hemoglobin has a quaternary structure. It consists of two pairs of different proteins, designated the and chains.

Detailed explanation-3: -In contrast to the first three levels of protein structure, not all proteins will have a quaternary structure since some proteins function as single units. Protein quaternary structure can also refer to biomolecular complexes of proteins with nucleic acids and other cofactors.

Detailed explanation-4: -Typically, a protein with a quaternary structure will be composed of either two or four subunits and called dimer or tetramer, respectively. Proteins are composed of 3, 5, 6, or more subunits.