BIOMOLECULES AND ENZYMES

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: -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-3: -Tertiary structure-the level of protein structure at which an entire polypeptide chain has folded into a three-dimensional structure. In multi-chain proteins, the term tertiary structure applies to the individual chains.

Detailed explanation-4: -Answer and Explanation: When two protein chains combine to form an active protein, the structural level is quaternary. This exists in proteins with more than one polypeptide chains or subunits that form assemblies bound together by noncovalent interactions.

Detailed explanation-5: -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.