CARBOHYDRATES

By: Amit Sharma, Japjit SinghMs. Topp

CarbohydratesO Carbohydrates are a type of biological molecules

that always contains carbon,hydrogen, and oxygen(CH2O)

O There is 2 Hydrogen molecules and 1 oxygen molecule for every carbon molecule.

O General formula for carbohydrates is written as (CH2O)n, n stands for number of carbon atoms.

O Carbohydrates have two main functional groups which are carbonyl and carboxyl.

O There four types of Carbohydrates : Monosaccharides Disaccharides Oligosaccharides Polysaccharides

MonosaccharidesO There are three to seven carbon atoms,

which is a simple sugarO They are called monosaccharides because

they are composed of single carbon based monomer structure

O Glucose is an example of a monosaccharide – its usually called blood sugar because it is the first source of energy for cells in the body.

O Fructose – called fruit sugar because it a principal sugar in fruits.

O Another ex. Is Galactose which is found in milk as sugar.

Monosaccharides Cont’d

O Glucose, Fructose, Glactose are all examples of isomers, which means they have the same chemical formula but structure differently

O These slight changes in structures are enough for molecules to be treated differently by your body.

O An ex.; your taste will detect fructose to be sweeter the glucose.

DisaccharidesO Disaccharides are formed when two

monosaccharides join.O The covalent bond between two

monosacchardies is called glycosidic linkage.O Glycosidic linkage forms between hydroxyl

groups on each monosaccharides.O Ex. Comman Table Sugar is a disaccharides

sucrose which is formed from glucose and fructose.

O Galactose and glucose bond to form disaccharides lactose.

O Some human’s body cells cannot breakdown lactose making them lactose intolerant.

Polysaccharides O Many monosaccharides can join together by

glycosidic linkage to form a polysaccharide.O Ex. of polysaccharides: Strach Glycogen CelluloseO All these are composed of monomers of

glucoseO The polysaccharide ‘Cellulose’ is in plant

cells which provides structural support.

Polysaccharides Cont’d

O The glycosidic linkage between monomers of cellulose is different from starch and glycogen.

O This difference can be because the hydroxyl group on Carbon-1 of glucose can exist in two different positions.

O Starch and glycogen are digestible by humans and many other animals because our body’s have enzymes that notice this glycosodic linkage.

O Cellulose is indigestible because we don’t have the required enzyme that recongizes the glycosodic linkage in that marcomolecule.

OligosaccharidesO Has two to ten monosaccharides.O Commonly found on the plasma

membrane of the animal cell, where they play the role of the cell-cell recognition

O Found O-linked