Question

Match list 1 with list 2 and select the correct answer using the codes given below the lists-

List 1	List 2
1.Muscle contraction	i. Zinc
2.Blue green algae	ii. Cobalt
3.Carboxypeptidase	iii. Calcium
4.Cyanocobalamin	iv. Molybdenum

A.1-iv; 2-iii; 3-; 4-ii
B.1-iii; 2-iv; 3-ii; 4-i
C.1-iv; 2-iii; 3-ii; 4-ii
D.1-iii; 2-iv; 3-I; 4-i

Answer 1

Calcium is stored in sarcoplasmic reticulum of muscles. Zinc is an activator to several enzymes. Molybdenum is present in excess amounts in organisms involved in nitrogen fixation.

Complete answer:
Calcium is essential for all living organisms and is used in cell walls, bones and some cells as structural components. In human blood, calcium ions are present mainly in the plasma in ionic as well as with combined serum proteins. It plays an important role in muscle contraction and stabilization of certain enzymes. It is also involved in blood clotting.
Cobalt is an essential trace element. It is essential for many organisms including mammals. It activates a number of enzymes. It is a constituent of vitamin ${{\text{B}}_{12}}$ which is required for the formation of hemoglobin. However, it is highly toxic to plants and moderately to mammals when injected in high amounts. Deficiency of cobalt in soil adversely affects the health of grazing animals. Adding cobalt to soil, improved their health.
Zinc is an essential element for almost all organisms. It is second only to iron in importance. Zinc plays an important biological role in the enzyme system of all animals and plants. It is used in more than 70 enzymes. It behaves as lewis acid in biochemical systems. Zinc containing enzyme carbonic anhydrase is vital for respiration in animals because it catalyses the normally slow carbonic acid-carbon dioxide reaction equilibrium. Carboxypeptidase is also zinc containing enzymes having some 300 amino acid residues including three methionyl residues. It is present in pancreatic juice and is primarily involved in the digestion of protein metabolism. Its function is to catalyze the hydrolysis of peptide bonds.
Molybdenum is an essential trace element for all organisms with the possible exception of green algae. It is constituent of several enzymes which are used by nature for nitrogen fixation and nitrate reduction. Molybdenum excesses in the biological system may cause copper deficiency and is associated with gout-like syndrome.

Thus, the correct option is D.
Note:
Cyanocobalamin is also known as vitamin ${{\text{B}}_{12}}$. The essential elements are those which are required for the maintenance of life of plants and animals. Bulk elements are those which are found in higher concentrations. Trace elements are needed in low concentration.