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Biomolecules - Vitamins (Classification and Functions)

Grade 12CBSEChemistry

Review the key concepts, formulae, and examples before starting your quiz.

🔑Concepts

Vitamins are organic compounds required in the diet in small amounts to perform specific biological functions for normal maintenance of optimum growth and health of the organism.

Classification based on solubility: Fat-soluble vitamins (Vitamins A,D,E,A, D, E, and KK) are soluble in fats and oils but insoluble in water. They are stored in liver and adipose (fat storing) tissues.

Water-soluble vitamins: Vitamins of BB group (B1,B2,B6,B12B_1, B_2, B_6, B_{12}, etc.) and Vitamin CC are soluble in water. They must be supplied regularly in diet because they are readily excreted in urine and cannot be stored (except Vitamin B12B_{12}) in our body.

Vitamin HH (Biotin) is an exception as it is neither soluble in water nor in fat.

Important Vitamins and Deficiency Diseases: Vitamin AA (Xerophthalmia/Night blindness), Vitamin B1B_1 (Beri-beri), Vitamin B2B_2 (Cheilosis), Vitamin B12B_{12} (Pernicious anaemia), Vitamin CC (Scurvy), Vitamin DD (Rickets/Osteomalacia), Vitamin EE (Increased fragility of RBCs/Muscular weakness), Vitamin KK (Increased blood clotting time).

Vitamin CC is chemically known as Ascorbic Acid (C6H8O6C_6H_8O_6) and is found mainly in citrus fruits.

📐Formulae

C6H8O6 (Vitamin C / Ascorbic Acid)C_6H_8O_6 \text{ (Vitamin C / Ascorbic Acid)}

C20H30O (Vitamin A / Retinol)C_{20}H_{30}O \text{ (Vitamin A / Retinol)}

C63H88CoN14O14P (Vitamin B12 / Cyanocobalamin)C_{63}H_{88}CoN_{14}O_{14}P \text{ (Vitamin B}_{12} \text{ / Cyanocobalamin)}

C28H44O (Vitamin D2 / Ergocalciferol)C_{28}H_{44}O \text{ (Vitamin D}_2 \text{ / Ergocalciferol)}

💡Examples

Problem 1:

Why cannot Vitamin CC be stored in our body?

Solution:

Vitamin CC is a water-soluble vitamin.

Explanation:

Because it is soluble in water, it is readily excreted from the body through urine and is not stored in the liver or adipose tissues like fat-soluble vitamins. Therefore, it must be supplied regularly in the diet.

Problem 2:

Name the vitamin whose deficiency causes 'Pernicious Anaemia' and mention its unique metallic constituent.

Solution:

Vitamin B12B_{12} (Cyanocobalamin); Central metal atom: CoCo (Cobalt).

Explanation:

Vitamin B12B_{12} is essential for the maturation of Red Blood Cells (RBCsRBCs). Its deficiency leads to a decrease in RBCsRBCs, a condition known as pernicious anaemia. It contains a coordination complex of Cobalt (Co3+Co^{3+}).

Problem 3:

A person is suffering from the lengthening of blood clotting time. Which vitamin deficiency is likely responsible?

Solution:

Vitamin KK (Phylloquinone).

Explanation:

Vitamin KK is essential for the synthesis of prothrombin and other clotting factors in the liver. A deficiency of Vitamin KK results in a decrease in these factors, leading to delayed blood coagulation and increased bleeding tendencies.

Vitamins (Classification and Functions) Revision - Class 12 Chemistry CBSE