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Many enzymes catalysed the reaction of their substrate only in the presence of a specific organic molecule called co-enzyme.
Co-enzyme frequently, B-vitamins as a part of their structure. Coenzymes are dialyzable organic compounds which are non covalently bound to enzyme protein and are responsible for the catalytic activity of several enzymes. Co-enzymes are generally derived from the water soluble vitamins and carry out ransfer of hydrogen or any other group of substarate in an enzimic reaction.
Folic acid acts as a coenzyme for transfer and utilization of formate C1 fragment in the form of tetrahydrofolic acid. It is used in the treatment of macrocytic anaemia. It takes part in purine nucleotide synthesis and thymidylate synthesis. Folic acid consist of pteridine nucleus, P aminobenzoic acid and glutamic acid.
1) Vitamin B12 along with folic acid is essential for the development of red blood cells beyond megaloblast stage.
2) It acts a coenzyme in the conversion of methyl malonyl CoA to succinyl CoA.
3) It is required in the conversion of ribonucleotides to deoxyribonucletides.
4) Its coenzyme acts in transfer of methyl group.
Pernicious anemia or Macrocytic anemia is a deficiency symptoms of vit. B12. This is associated with lesions of the CNS described as subacute combined degeneration, due to the interference with the normal synthesis of nucleic acids, particularly DNA.
Chemistry- The structure of vitamin B12 consists of
1) Tetrapyrrole ring system-corrin
2) Cobalt occupying central place in the rig
3) Cynide is attached to cobalt
4) A nucleotide and
5) 6- methy benzinamidazole riboside which is attached at the one end to cobalt and at the other end to a side chain in ring IV through phosphate.
The deficiency of vitamin B1 produces a condition on called as “Beri-Beri”. The deficiency symptoms include anorexia, loss of weight, muscle cramp and general muscular weakness. The Beri -Beri has essentially two components i) cardio-vascular failure leading to enlargement of heart and edema and ii) neutral components viz. Peripheral neurisis. A deficiency in pigeons produces a disease characterized by loss of appetite, paralysis and heart retraction.
Thiamine is awater soluble B group vitamin. The molecule cantains a hydrochloride is a commonly used salt. The molecule contains a Pyrimidine ring and a thiazole ring linked by a methylene group. The nitrogen of two thiazoles ring is cationic and associated with chloride ion. The crystalline hydrochloride is a salt formed with weakly a bacisamino group. Thiamine hydrochloride occurs as a colourless crystal r white or almost white crystalline powder with a characteristic meat like odour and bitter taste. It is freely soluble in water. It is incompatible with oxidizing and reducing substance, mercuric chlorides, iodides, carbonates and ferric sulphate.
1) It is involved in oxidation-reduction of the cell. It is a donor of reducing equivalents in certain key reaction.
2) It is involved in the conversion of folic acid to the active form, tetrahydrofolic derivative.
3) It is involved in tyrosine metabolism i.e. oxidation of p-hydroxyphenyl pyruvate to homogentisate.
4) It is used in absorption of iron by converting the inorganic ferric iron to the ferrous form.
5) It is essential for the activity of fibroblasts, osteoblasts and odonoblasts. It causes hydroxylation of proline in collagen synthesis.
Chemistry-
Vitamin c is also known as antiscorbutic vitamin. It is found in all living plant cells, it is an endiolaction, which is readily oxidized to dehydroascorbic acid. It is, therefore a good reducing agent. Both oxidized and reduced fiorms of vitamin are biologically active. It occurs as a white crystalline powder with faint yellowish tint. It is freely soluble in water.
Vitamin ‘k’ defines generally occurs due to its defective absorption from intestine or due to the inhibition of intestinal bacteria as happens in antibiotic and sulphonamic therapy. Following are the important deficiency manifestation.
1) Hypoprothrombinemia in which the blood clotting time is prolonged.
2) Uncontrolled haemorrhages.
Compound having vitamin k activity are naphthoquinone, chemically it is a phytomenadione. The two naturally occurring vitamin k are vitamin K1 and vitamin K2.
Biochemical function-
1) It reduces the prothrombin time.It is associated with the electron-transport chain and oxidation phosphorylation
1) It protects Vitamin A and carotenes from destruction by oxidation in the body.
2) It prevents the formation of peroxides by polyunsaturated fatty acids and also the pigmentation of adipose tissue.
3) It protects enzymes in muscle, nerve or gonads from destruction
4) It prevents the hepatic necrosis produced by the lake of sulfur caintaining amino acids in dietary proteins.
5) It prenvents the development of encephalomalacia and exudative diathesis in chicks.
1) vitamin D increases the absorption of calcium and phosphorous from the intestine and maintain their regulated supply to body fluids.
2) It increases the calcification of bones in body adults and growing childrens.
3) It increases the excretion of phosphate by kidney and lowers the serum phosphate concentration.
4) It increases the citrate level of blood, bone, kidney and heart tissue as well as the excreation of citric acid.
5) It decreases th PH in the lower intentinal tract which helps in increasing the absorption of calcium and phosphorous.
Deficiency of vitamin D results into “ Rickets” which is characterized by lack of calcification of hypertrophic cartilage zone and thus the bones are affected. Vitamin D plays an important role in the absorption of calcium and phosphorus from intestinal tract. In ricketier persons the phosphate blood serum level is high which is brought down to a normal value by this vitamin. Vitamin D is used in rickets and for the management of hypocalcemia. In fully grown bones in adults there is a tyupe of deective mineralization of ostoid tissue termed as Osteomalacia
Add 10 drops of Huble’s Iodine reagent to 10ml of chloroform. Chloroform assumes a pink color due to the free iodine. The solution is divided equally into the test tubes.
Add the oil number 1 to the test tube by drop shaking the tube vigorously after each addition till the pink colour of the solution just disapper. The number of oil drops required are noted. The experiment is repeated by oil 2 and 3 adding to test tubes. The more number of drops required to discharge the pink colour, the less is the unsaturation.
The essential fatty acids of vegetables oils have low melting point and Iodine number. Theyu become saturated fatty acids on hydrogenation and oils become solid fats.
Functions-
1) The essential fatty acid in high concentration along with the lipids constitutes the structural elements of tissue.
2) Lipids of gonads also contain aa high concentration of poly-unsaturated fatty acis which suggest the importance of reproductive function.
3) They affect the prolongation of clotting time and increase the fibrinilytic activity.
4) They retard atherosclerisis being esterified and emulsified with cholesterol and are incorporated into lipo-proteins for transport of liver for further oxidation.
5) They cure skin lessons.
6) They deficiencies of these acids in the diet of babies causes eczema.
The saturated fatty acids, which are not synthesized in the body and required for the growth and health, are called fatty acids. They are supplied for the diet. These are-
1) Linoleic acid
2) Linolenic acid
3) Arachidinic acid
The essential fatty acids in the high concentration along with structural elements of tissue lipid of gonads. It also contain high concentration of poly-unsaturated fatty acids, which suggest the importance of reproductive function. They affect the prolongation of clotting time and increase the fibrinolytic activity. They cure the skin lesions.
Fatty acids are the derived lipids and are obtained by the hydrolysis of fats and other lipids. Naturally occurring fatty acids contain an even number of carbon atom because they are synthesized from 2 carbon units and are strainght cahin derivatives. The straight chain may be saturated or unsaturated and depending on this, fatty acids may be 1)saturated fatty acids 2) unsaturated fatty acids.
1) Saturated fatty acids- Straight chain saturated hydrocarbon belonging to acetic acid series, and have the general formula.
2) Unsaturated fatty acids- Fatty acids which have one or more double bonds in their molecules are called unsaturated fatty acids.
These are the compound lipids found in plasma and cell membrane. The lipid constituents of lipoproteins are mostly esterified cholesterol and phosholipids. The most important role of lipoproteins in the body is to transport and deliver the lipids to tissue and to maintain the structural integrity of cell surface and subcellular particles like mitochondria and microsomes. The four major groups have been identified
a) Chylomicrons
b) Very Low Density Lipoproteins
c) Low Density Lipoproteins
d) High Density Lipoproteins
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