Question

Metals present in insulin and haemoglobin respectively are:
(A) $Zn,Hg$
(B) $Zn,Fe$
(C) $Co,Fe$
(D) $Mg,Fe$

Answer 1

Think about the functions of insulin and haemoglobin in our body. Consider the elemental metals that will be most suitable to carry out the respective functions. Also, consider daily life experiences to narrow down the options.

Complete step by step solution:
First, let us look at the functions of insulin and haemoglobin before moving on to their structures.
- Insulin
It is a peptide hormone that is produced by a type of cell called the $\beta$ - cells in the pancreas. The job of this hormone is to regulate the metabolism of complex carbohydrates into glucose. It is the primary anabolic (causes breakage of complex molecules to simple molecules) hormone that controls blood sugar levels by either the storage of glucose in the liver or by the consumption of glucose to form ATP units (energy currency). The chemical formula of insulin is ${{C}_{257}}{{H}_{383}}{{N}_{65}}{{O}_{77}}{{S}_{6}}Zn$.
Thus, insulin contains the element of zinc.
- Haemoglobin
Haemoglobin is a metalloprotein that is found in the red blood cells of all mammals. It imparts the red colour to blood and acts as a transporter for oxygen from the lungs to the heart and then the other parts of the body. It also has the ability to carry carbon dioxide which is how it carries the waste product of metabolism from the tissues to the lungs for expiration. The chemical formula of haemoglobin is $~{{C}_{738}}{{H}_{1166}}{{N}_{812}}{{O}_{203}}{{S}_{2}}Fe$.

Hence, the correct answer to this question is ‘B. $Zn, Fe$’

Note: Remember that many of the essential nutrients that we require for growth are complicated molecules that are complexes of some transition metals. These complex nutrients are essential for the growth of human beings. The pigment chlorophyll with the chemical formula ${{C}_{55}}{{H}_{72}}{{O}_{5}}{{N}_{4}}Mg$ and the vitamin ${{B}_{12}}$ with the molecular formula ${{C}_{63}}{{H}_{88}}Co{{N}_{14}}{{O}_{14}}P$ are some such important organometallic complexes.