Question

Is Haemoglobin a Tertiary or quaternary structure?

Answer 1

Haemoglobin is a Quaternary structure.

Quaternary structure of Haemoglobin: The molecular structure of haemoglobin was first described by Max Perutz in 1959, Haemoglobin is a tetrameric protein, The two subunits of the “and ”polypeptide chains form the major type of haemoglobin found in adults.

1. Each polypeptide chain has a heme prosthetic group attached to it next.
2. A subunit is a protein composed of an alpha polypeptide chain with $141$ amino acid residues, It is a subunit and is composed of a $146-$residue beta polypeptide chain.
3. Each polypeptide chain is joined together by a prosthetic group called a heme group, which contains iron. The central component of the porphyrin ring is iron.
4. The relationship between subunits is quite strong.
5. On the modest treatment of urea, haemoglobin partially dissociates, but the dimers remain unaffected. Some ion pairs or salt bridges, hydrogen bonds, and predominantly hydrophobic interactions hold the subunits together.

Hence, Haemoglobin is a Quaternary structure.