NEET BIOLOGY

Detailed explanation-1: -Quaternary structure exists in proteins consisting of two or more identical or different polypeptide chains (subunits). These proteins are called oligomers because they have two or more subunits. The quaternary structure describes the manner in which subunits are arranged in the native protein.

Detailed explanation-2: -Quaternary structure in proteins is the most intricate degree of organization still considered a single molecule. To be considered to have quaternary structure, a protein must have two or more peptide chains forming subunits. The subunits can be different or identical, and in most cases they are arranged symmetrically.

Detailed explanation-3: -Quaternary structure is the interaction of two or more folded polypeptides. Many proteins require the assembly of several polypeptide subunits before they become active. If the final protein is made of two subunits, the protein is said to be a dimer.

Detailed explanation-4: -Tertiary structure is the overall 3D structure of the protein. Quaternary structure is the overall structure that arises when separate protein chains aggregate with self to form homodimers, homotrimers, or homopolymers OR aggregate with different proteins to form heteropolymers.

Detailed explanation-5: -Finally, the quaternary structure of a protein refers to those macromolecules with multiple polypeptide chains or subunits.