Question

The red colouring pigment Haemoglobin in our blood contains which metal ?

• A. Fe
• B. Co
• C. Mg
• D. Na

Hint:

Think "Haem" sounds like "Heme", which contains Iron. % Option (U) {Haem}oglobin (in blood) \(\rightarrow\) contains {Fe} (Iron) - for oxygen transport. % Option (V) {Chl}orophyll (in plants) \(\rightarrow\) contains {Mg} (Magnesium) - for photosynthesis. Iron deficiency can lead to anemia because less haemoglobin can be made.

Answer 1

The Correct Option is A

Concept: Haemoglobin (often spelled Hemoglobin) is a protein in red blood cells responsible for transporting oxygen in the blood of vertebrates and some invertebrates. Its structure includes a metal ion. Step 1: Structure and Function of Haemoglobin Haemoglobin is a complex protein containing a non-protein component called haem (or heme). Each haem group contains a central metal atom. This metal atom is crucial for the oxygen-binding capacity of haemoglobin. The primary function of haemoglobin is to bind to oxygen in the lungs (or gills) and transport it to the tissues throughout the body, where it releases the oxygen. Step 2: The Metal in Haemoglobin The metal atom at the center of each haem group in haemoglobin is Iron (Fe). Specifically, it is an iron(II) ion, \(Fe^{2+}\). Each haemoglobin molecule typically has four haem groups, and thus can bind up to four oxygen molecules. The binding of oxygen to the iron atom is what gives oxygenated blood its bright red color, while deoxygenated blood is a darker red/purplish. Step 3: Analyzing the options % Option (Q) (1) Fe (Iron): Correct. Iron is the central metal atom in the haem group of haemoglobin. % Option (R) (2) Co (Cobalt): Cobalt is the central metal atom in Vitamin B12 (cobalamin), but not in haemoglobin. % Option (S) (3) Mg (Magnesium): Magnesium is the central metal atom in chlorophyll, the pigment responsible for photosynthesis in plants, but not in haemoglobin. % Option (T) (4) Na (Sodium): Sodium is an important electrolyte in the body (as \(Na^+\) ions) involved in nerve function and fluid balance, but it is not the metal in haemoglobin. Therefore, the metal in haemoglobin is Iron (Fe).