Wtite about polysaccharides with starch and cellulose as examples.

Explanation

Polysaccharides : The saccharides which on hydrolysis to form large number of monosaccharides are called polysaccharides
Eg: Starch and cellulose
Starch :
`to` Starch is the most important dietary source for human beings.
`to` Vegetables , roots , cereals are important sources of starch.
`to` It is a polymer of `alpha` - glucose.
`to` It is constituted by two components Amylose and amylopectin
Amylose :
`to` It constitutes 15-20% of starch
`to` Amylose is water soluble component.
`to` Amylose is a branched chain with 200-1000 `alpha` - D- glucose units held by C-1 to C-4 glycosidic linkage .
Amylopectin :
`to` Amylopectin constitutes 80-85% of starch.
`to` It is a branched chain polymer of `alpha` - glucose units in which chain is formed by C-1 to C-4 glycosidic linkage whereas branching occurs by C-1 to C-6 glycosidic linkage
Cellulose :
`to` Cellulose occurs in plants and it is the most abundant organic substance.
`to` It is a major constituent of cell wall of plant cells
`to` Cellulose is a straight chain polysaccharide composed only `beta` - D - glucose units which are joined by glycosidic linkage between C-1 of one glucose and C-4 of the next glucose .