CARBOHYDRATES By: Amit Sharma, Japjit Singh Ms. Topp

Carbohydrates O 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

Monosaccharides O There are three to seven carbon atoms, which is a simple sugar O 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.

Disaccharides O 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  Cellulose O All these are composed of monomers of glucose O 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.

Oligosaccharides O 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