Question

The metal essential for haemoglobin formation.
A. $M{g^{ + + }}$
B. $N{a^ + }$
C. $F{e^{ + + }}$
D. $C{u^{ + + }}$

Answer 1

Hint: Haemoglobin is made up of two words 'haem' and 'globin'. Globin is the protein part of the haemoglobin and haem is the prosthetic part of the non-protein part. Globin is present in a major amount in the haemoglobin as compared to haem part. Haemoglobin is essential in the transport of oxygen in the body. Haemoglobin is present in the red blood cells and it is the characteristic respiratory protein in humans.

Complete answer:
There are three types of proteins namely simple proteins, compound proteins and derived proteins. The compound proteins are further made up of the proteinaceous part and non-proteinaceous part. The non-proteinaceous part is called a prosthetic group. Each molecule of haemoglobin carries four molecules of oxygen, thus transporting the oxygen throughout the body.
The globin part of haemoglobin is composed of four polypeptide chains- alpha, beta, gamma, and delta. Based on these polypeptide chains, there are three types of haemoglobin found. These are adult haemoglobin (two alpha and two beta chains) another type of adult haemoglobin (two alpha and two delta chains) and fetal haemoglobin (two alpha and two gamma chains).
The haem part of haemoglobin is made up of metal and a ring called porphyrin ring. The metal essential for haemoglobin formation is iron in the form of $F{e^{ + + }}$. Porphyrin ring is the excretory substance and it is broken down into bilirubin and biliverdin pigments in the liver.

Hence, the correct answer is option (C).

Note: Oxygen is transported in the body by the two main methods. A very little amount of oxygen travels through plasma in the dissolved state. Rest of the quantity of it is transported through haemoglobin in the form of oxyhaemoglobin. Oxygen can reversibly bind with haemoglobin to form oxyhaemoglobin. At the tissue level, this oxygen is freed from haemoglobin and carbon dioxide binds with haemoglobin.