LIFE SCIENCE

Detailed explanation-1: -However, some proteins are made up of multiple polypeptide chains, also known as subunits. When these subunits come together, they give the protein its quaternary structure .

Detailed explanation-2: -The full three-dimensional organization of a polypeptide chain is sometimes referred to as the protein’s tertiary structure, and if a particular protein molecule is formed as a complex of more than one polypeptide chain, the complete structure is designated as the quaternary structure.

Detailed explanation-3: -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-4: -Quaternary (4˚) Structure 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-5: -The quaternary structure of a protein is the association of several protein chains or subunits into a closely packed arrangement. Each of the subunits has its own primary, secondary, and tertiary structure. The subunits are held together by hydrogen bonds and van der Waals forces between nonpolar side chains.