Disaccarides

 TOPIC#6    TYPES OF CARBOHYDRATES

2-OLIGOSACCHARIDES:

 OLIGO stands for few and SACCHARIDES stands for sugars.

 The type of carbohydrates which hydrolyzed to form 2-10 simple monosaccarides units on addition of water.

These units are link with each other by bond called as GLYCOSIDIC BOND.

GLYCOSIDIC BOND:

The bond formed between two monosaccharide units with removal of water is called glycosidic bond.

    glucose + fructose - sucrose + water (alpha 1-2 glycosidic bond)

    glucose + galactose - Lactose + water(beta 1-4 glycosidic bond)

    glucose + glucose - maltose +water (alpha 1-4 glycosidic bond)

Properties of Oligosaccarides:

They are crystalline sugars and glycosidic bond is also crystalline.

They form 2- 10 monosaccharides units on hydrolysis.

The oligosaccharides which hydrolyze into simpler units are called as disaccarides and those which hydrolyzed into 3 units called trisaccharides and so on till to 10.

Disaccharides are common in nature.

Examples of disaccharides are maltose(glucose+glucose) found in fruits and also found in our digestive tract.

Lactose is also dissacharide found in milk on hydrolysis convert into glucose and galactose in presence of enzyme lactase.

Sucrose is also disaccharide found in sugarcane on hydrolysis produce glucose and fructose in presence of enzyme sucrase.

Oligosaccharide are slightly soluble in water.

They are also sweeter in nature but less sweeter than monosaccharides and more sweeter than polysaccharides.

IN NEXT BLOG WE WILL DISCUSSED THE POLYSACCARIDES.