BIOMOLECULES AND ENZYMES

Detailed explanation-1: -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.

Detailed explanation-2: -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-3: -The quaternary structure is held together by a combination of Hydrogen bonds, disulphide bridges and Ionic bonds. They often also contain an inorganic group called a prosthetic group. An example of a quarternary protein that contains the prosthetic Haem group is Haemoglobin.

Detailed explanation-4: -Finally, the quaternary structure of a protein refers to those macromolecules with multiple polypeptide chains or subunits.

Detailed explanation-5: -The correct answer is option (C) Maybe either alpha or beta and depends on the primary structure of subunits. Note: Proteins consisting of two or more similar or various polypeptide chains (subunits) occur in proteins. Since they have two or more subunits, these proteins are called oligomers.