When a large number of monosaccharide units are joined together by a glycosidic linkage then polysaccharides are formed. These are commonly found in nature. They also act as food storage or structural materials.
First of all, let us discuss about starch from where we will move on to other polysaccharides such as Glycogen and Cellulose.
- Starch: It is one of the most important dietary sources for human beings and is also one of the main storage polysaccharide of plants. We can find high content of starch in cereals, roots and also in some other vegetables. It is a polymer of α-glucose and it mainly contains two components- Amylose and Amylopectin. Of these, Amylose is soluble in water and contains around 15-20% of starch. Chemically we can say that Amylose is long unbranched chain with α-D+ glucose units which are around 200-1000 in number and are connected by C1-C4 glycosidic linkage. The starch content in Amylopectin is about 80-85% but this is not soluble in water. It is a branched chain polymer and is formed by C1-C4 linkage by C1-C6 glycosidic linkage the branching starts.
- Cellulose: This is one of the most abundant organic substances that are present in plant kingdom. It is one of the major constituents of the plant cells. These are the polysaccharide which forms straight chain and is composed of only β -D-glucose units and are joined by glycosidic linkage between the first carbon of the glucose unit and fourth carbon of the next glucose unit.
- Glycogen: In an animal’s body the carbohydrates are stored in the form of glycogen. This is also called as animal starch as its structure is somewhat similar to amylopectin and it has many branches. It is present in liver, muscles as well as in brain. The enzymes break down the glycogen into glucose whenever the body needs it. We can also find glycogen in yeast and fungi. For any other information contact our Byju’s mentors who are always there to help you.