BIOMOLECULES AND ENZYMES

Detailed explanation-1: -Hemoglobin has a quaternary structure. It consists of two pairs of different proteins, designated the and chains. There are 141 and 146 amino acids in the and chains of hemoglobin, respectively. As in myoglobin, each subunit is linked covalently to a molecule of heme.

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 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: -The structure for hemoglobin is very similar to myoglobin except that it has a quaternary structure due to the presence of four protein chain subunits. Actually, there are two pairs of similar chains-two alpha types and two beta types. Each protein chain subunit contains a heme group with the iron attached.

Detailed explanation-5: -It is composed of four protein chains, two alpha chains and two beta chains, each with a ring-like heme group containing an iron atom.