Question

What is the name of the linkage connecting the monosaccharides in the polysaccharide ?

Answer 1

Hint : Monosaccharide is a carbohydrate composed of simple elements carbon $C$ , hydrogen $(H)$ , and Oxygen $(O)$ . Two monosaccharide molecules form a bond that results in a disaccharide molecule. Some common examples of the disaccharides are – sucrose, maltose, and lactose.
When more than two monosaccharides join each other and form a bond that results in a polysaccharide.

Complete Step By Step Answer:
To solve this question first we need to understand carbohydrates and composition of the disaccharides or polysaccharides.
Carbohydrates are the naturally occurring compounds. These have four main categories – Monosaccharide, disaccharide, oligosaccharide and polysaccharide.
Carbohydrates are simple sugars and the disaccharides are known as “double sugars ``because they are composed of two monosaccharide units joined by ether bonds. They have $\alpha ,\beta$ - glycosidic linkage. And the hemiacetal hydroxyl group resulting from the oxygen always participates in bond formation. Whether it is disaccharide or polysaccharide , in them monosaccharides are joined by Glycosidic linkage .
And the general formula for the disaccharides are ${C_{12}}{H_{22}}{O_{11}}$ .
And the general formula for the polysaccharides are ${C_6}{H_{10}}{O_5}$
Some common disaccharides are
$sucrose = glucose + fructose$
$Maltose = glucose + glucose$
$Lactose = glucose + galactose$
Some common polysaccharides are - starch glycogen and cellulose .
Starch is made up of repeating units of glucose
Let’s look at the structure of the maltose (disaccharides) to understand its composition.
Maltose consists of two molecules of glucose joined by $\alpha - 1,4 -$ glycosidic linkage. During the bond formation water molecules are released.

In case of maltose only one hemiacetal hydroxyl group participates in bond formation and the second one retains the properties of a reducing sugar.
Now , let's look at the polysaccharide starch consisting of glucose molecules joined by glycosidic bonds .

Note :
It is to keep in mind that the non – reducing nature of some disaccharides such as sucrose and trehalose is advantageous also as they confer these double sugars stability. And stability is the major criteria for the storage of the sugar, this is the reason why sucrose is also known as “table sugar”.