Which element is called a protein in haemoglobin?

Correct option is A

The Correct Answer is Haemoglobin
Haemoglobin is the protein in red blood cells responsible for transporting oxygen from the lungs to the tissues and returning carbon dioxide to the lungs. It is a complex protein made up of four globin chains, each attached to a haem group. The haem group contains iron, which gives blood its red colour and is the actual binding site for oxygen.
Haemoglobin is not just a pigment but a functional protein—its structure and function are essential for respiration and oxygen delivery throughout the body. It is thus referred to as the main protein component in red blood cells.
Information Booster:
· Haemoglobin = Haem (iron-containing pigment) + Globin (protein chains)
· It consists of four polypeptide chains (2 alpha and 2 beta in adults), each linked to one haem group.
· Each haem group can bind one oxygen molecule, allowing each haemoglobin molecule to carry up to 4 oxygen molecules.
· The presence of iron in haem enables reversible oxygen binding, which is essential for efficient oxygen transport.
Additional Knowledge:
· Globin: This is the protein subunit of haemoglobin, but not the full protein; haemoglobin as a whole is the complete oxygen-carrying protein.
· Lipoprotein: These are compounds of lipids and proteins that help transport cholesterol and fats in the blood, not involved in oxygen transport.
· Haem: This is the iron-containing pigment part of haemoglobin, not the entire protein.