Question

Haemoglobin has 4 subunits while myoglobin has only 1 subunit. Then each will show which among the following conformations respectively?

• A. $1^{\circ }$, $2^{\circ }$, $3^{\circ }$, $4^{\circ }$ and $1^{\circ }$, $2^{\circ }$, $3^{\circ }$
• B. 1 ̊, 2 ̊, 3 ̊, 4 ̊ and 1 ̊, 2
• C. $1^{\circ }$, $2^{\circ }$, $3^{\circ }$ and $1^{\circ }$, $2^{\circ }$, $3^{\circ }$, $4^{\circ }$
• D. $1^{\circ },2^{\circ },3^{\circ }$ and $1^{\circ },2^{\circ }$

Answer 1

The correct option is A $1^{\circ }$, $2^{\circ }$, $3^{\circ }$, $4^{\circ }$ and $1^{\circ }$, $2^{\circ }$, $3^{\circ }$

All proteins have primary, secondary and tertiary structures but quaternary structures only arise when a protein is made up of two or more polypeptide chains.
Hemoglobin is the oxygen-transporting protein of red blood cells and is a globular protein with a quaternary structure. Hemoglobin consists of four polypeptide subunits; 2 alpha chains and two beta chains.
Unlike haemoglobin, myoglobin does not have a quaternary structure, as it consists of a single polypeptide chain.