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ZOOLOGY: SEM- III, PAPER- C7T: FUNDAMENTALS OF BIOCHEMISTRY, UNIT 1: CARBOHYDRATES

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ZOOLOGY: SEM- III, PAPER- C7T: FUNDAMENTALS OF BIOCHEMISTRY, UNIT 1: CARBOHYDRATES

Carbohydrate derivatives are sugar molecules that have been modified with substituents other than hydroxyl groups.

Examples include glycosylamines, sugar phosphates, and

sugar acetates. Most sugar derivatives occur naturally and

have important biological functions. For instance,

chondroitin sulfate is an important structural component

of cartilage and provides much of its resistance to

compression.

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Derivatives of Monosaccharides:

Derivatives of monosaccharides are found in nature.

One example of a monosaccharide derivative is

vitamin C, also called ascorbic acid, which is derived

from glucose. Sugar substitutes, such as sorbitol and

mannitol, are used as sweeteners, and they form

naturally in plants and berries from monosaccharides

like glucose and mannose. Amino sugars, such as

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glucosamine, a derivative of glucose, produce

cartilage, connective tissue and chitin, a component of

an insect’s exoskeleton.

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Some important derivatives of monosaccharides are as follows:

(a) Deoxyribose:

The deoxygenation of ribose at C-2 position produces deoxyribose. It is important component of deoxyribonucleotides of DNA.

(b) Phosphorylated sugars:

The transfer of phosphorylated group from ATP to -OH group of a

sugar produces phosphorylated sugar, e.g. glucose-6-phosphate.

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The phosphorylated sugars are anionic which prevent their escape from cell and also acts as reactive intermediates.

(c) Sugar alcohol:

It is formed by reduction of aldehyde and ketone group of sugar, e.g., mannitol, glycerol, sorbitol etc. Mannitol is a sugar alcohol in brown algae, some fruits and honey. It is used as a medicine for patients with brain edema. Glycerol required in fat synthesis.

Sorbitol, a sugar alcohol commercially obtained from reduction of

glucose and fructose, is used in diets of diabetics because it is

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absorbed very slowly and metabolized after conversion to glucose, but it does not raise blood sugar.

(d) Sugar acids:

Ascorbic acid or vitamin-C is a sugar acid required for collagen synthesis. Glucouronic acid and iduronic acid are components of mucopolysaccharides.

(e) Amino sugars (hexosamines):

Glucosamine forms chitin and hyaluronic acid.

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Some more Carbohydrate Derivatives are:

Glucose Family:

i. β-D-Glucose

ii. β-D-Glucose-6-Phosphate iii. β-D-Glucosamine

iv. N-Acetyl-β-D-Glucosamine v. N-Acetylmuramic Acid

vi. β-D-Glucuronate

vii. β-D-Gluconate

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Artificial Sweeteners:

i. Aspartame ii. Saccharin iii. Sucralose Amino Sugars:

i. N-Acetylglucosamine ii. Galactosamine

iii. Glucosamine

iv. Sialic acid

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L-Daunosamine Deoxy Sugars:

i. Deoxyribose ii. Fucose

iii. Rhamnose

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A large number of biologically important modified monosaccharides exist:

Amino sugars such as:

I. galactosamine II. glucosamine III. sialic acid

IV. N-acetylglucosamine

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Sulfosugars such as:

sulfoquinovose Others such as:

ascorbic acid mannitol

glucuronic acid

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Carbohydrate Derivatives containing drugs are:

Fergon:

Generic Name: Iron(II) gluconate, or Ferrous gluconate It is the iron(II) salt of gluconic acid.

Brand Name: FE-40 and Fergon

General Formula: C

12

H

24

FeO

14

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Uses of Fergon:

1. It is effectively used in the treatment of hypochromic anemia.

2. It is used as an iron supplement to treat or prevent low blood levels of iron (such as those caused by anemia or pregnancy) since iron is an important mineral that the body needs to produce red blood cells and keep you in good health.

3. Fergon is also an essential body mineral.

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