Polysaccharide is formed from the Greek words poly meaning many and saccharin meaning sugar. Carbohydrates that break down or break down into many molecules (more than 10) of monosaccharides are called polysaccharides. Their common symbol is (C6H10O5)n. where 10 ≥ n ≤ 3000|
Properties of polysaccharides
(i) It is a complex sugar.
(ii) Its wet analysis yields numerous monosaccharide molecules.
(iii) It is a large molecule.
(iv) Its molecular weight is more than 10,000 daltons.
(v) It is not sweet in taste.
(vi) It is non-granular and insoluble in water.
(vii) It does not contain aldehyde and ketone groups.
(viii) It is an insoluble sugar.
1. Classification based on work
Polysaccharides are divided into three categories based on function.
(i) Stored polysaccharides: All the carbohydrates that are stored in the body as stored food are called stored polysaccharides. For example, starch, glycogen, inulin, dextin, paramylam, livan etc. Starch is the main stored food in plants and glycogen in animals. Dr. Siddiq Publications
(ii) Structural polysaccharides: Carbohydrates which form the cell walls of plants are called structural polysaccharides. For example, cellulose, hemicellulose, pectic acid, chitin, keratin sulfate etc. Cellulose is the main structural component of the cell wall.
(iii) Complex polysaccharides: Those polysaccharides which are composed of sugars and non-sugars are called complex polysaccharides. Such as mucopolysaccharide, agar, hyaluronic acid, chondroitin sulfate, heparin etc. Dr. Siddiq Publications
2. Structural classification
Polysaccharides are divided into two categories based on structure.
(i) Homopolysaccharides or Homoglycans: Carbohydrates that are composed of monosaccharides of the same type are called homopolysaccharides or homoglycans. For example, starch, cellulose, glycogen, inulin etc.
(ii) Heteropolysaccharides or Heteroglycans: Carbohydrates composed of two or more types of monosaccharides are called heteropolysaccharides or heteroglycans. Such as hemicellulose, mucopolysaccharide, pectin, chitin, agar etc.
3. Unit Based Classification: On the basis of structural unit polysaccharides are of several types-
(i) Glucosan: The polysaccharide formed from glucose is called glucosan.
(ii) Fructosan: The polysaccharide formed by fructose is called fructosan.
(iii) Galactasan: The polysaccharide formed by galactose is called galactasan.
(iv) Hexosan: A polysaccharide composed of six carbon monosaccharides is called hexosan.