MINISTRY OF DEFENCE

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  MINISTRY OF DEFENCE. Establishment Of National University In Islamabad Total position. 29 Domicile , All over Pakistan    Qualification  intermediate to bachelor positions . Project Engineer(Civil) account Officer  supervisor assistant office boy     How to apply.   Apply online through the link https://www.fgei-cg.gov.pk/nup-rec.php   Last date to apply  02 April 2023. No TA/DA Fo Interview 
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Polysaccharides

Polysaccharides:


  Definition 
Polysaccharides ( or simply glycans)
Consist of repeating unit of monsaccharides or their derivatives  held to gether by glycosidic bonds .
They perform two functions
1) structural or storage of energy
Types of polysaccharides
1) Homopolysaccharides 
2)Heteropolysaccharides
1) HOMOPOLYSACCHARIDES
On hydrolysis yield only a single type of monosaccahrides they are named based on the nature of the monosaccharides  thus glucans are polymers of glucose while fructosans are polymer of fructose

Examples
1) Starch 
2Dextrins
Cellulose 
4Glycogen 
Chitin 
Heteropolysaccharides
ON hydrolysis yield a mixture of  few monosaccharides and their derivatives 
Examples
1)Hyalunuric acid 
2) chondroitin sulphate 
3 Heparin

Homopolysaccharids (starch) 
Starch; 
 Starch is the carbohydrate reserve of plants which is the most important dietry source of higher animals including man  higher content of starch is found in cereals ,roots, tubers, vegetables starch is the homoploysaccharides  composed of D glucose held by glycosidic linkages starch consiats of teo polysaccharides  amylose and amylopectin ; amylose  15 to 20% and amylopectin is 80  to 85%
1 (AMYLOSE)
2( AMYLOPECTIN)
Amylose  is a long unbranched chain with 200-1000 D glucose  units held by glycosidic linkage and it is water soluble
Amylopectin 
On the other hand is a branched chain  with a 1-4 and 1-6  glycosidic linkage amylopectin molecule cintaining  a few thosands glucose units look like a  branched tree 20 -30 glucose units per branch
2DEXTRINS
Dextrins  are the hydrolytic products of starch by the enzyme amylase
GLYCOGEN
Glycogen is the carbohydrate reserve in animals hence known as animal starch it is present in high concentration in liver muscle and brain etc
Glucose is the repeating unit in glycogen 15000 units of glucose in per branch of glucose 1-4 and 1-6 linkage held by glycosidic bonds
CELLULOSE
Cellulose occurs  exclusively in plantsand it is a predominant contituent  of plant cell wall cellulose is totally absent in animal body  cellulose is composed of beta D glucose units linked by 1-4 linkage
CHITIN
Chitin is composed of N-Acetyl D-glucose amine units held together by (1-4)linkage glycosidic bonds it is a structural polysaccharides found in the exoskeleton of some invertebrates , insects and cristaceons

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