CARBOHYDRATES

Description:-Carbon, hydrogen and oxygen found in carbohydrates .The ratio of hydrogen to oxygen is 2:1, the same as in water. Although there are exception, carbohydrates generally contain on e water molecule for each carbon atom .This is the reason they are called ‘carbohydrates’ which means “watered carbon”

 

Types Of Carbohydrates:-Mainly carbohydrates are of three types,

                     1.Monosaccharides    2.Disaccharides       3. Polysaccharides 

 1.Monosaccharides:-Simple sugar that contain 3 to 7 carbon atom.

Examples-Glucose(the main blood sugar),Fructose(found in  fruits), Galactose (in milk), Deoxyribose (in RNA),Ribose (in DNA).

2.Disaccharides:-Simple sugar formed from the combination of two monosaccharides by dehydration synthesis for example molecules of monosaccharides glucose and fructose combine to form a molecule of the disaccharide sucrose (table sugar) as shown below

Disaccharides can also be split into smaller ,simpler molecules by hydrolysis. A molecule of sucrose , for example may be hydrolyzed  into its components , glucose and fructose , by the addition of water. In the above fig. you can easily understand.

 Example-sucrose =(glucose +fructose) lactose(milk sugar)=glucose+galactose , Maltose(glucose+glucose)

 

3 Polysaccharides :-   The third major group of carbohydrates  are polysaccharides. Each polysaccharides molecules contain tens or hundreds of monosaccharides joined through dehydration synthesis reaction.

Unlike simple sugar ,polysaccharides usually are insoluble in water and do not taste sweet. The main polysaccharide in the human body is glycogen, which is made entirely of glucose monomers.      

Example-Glycogen(stored in animals)  ,starch(stored in plants)  ,cellulose(parts of cell wall in plants that can not be digested by humans but aids movement of the food through intestine)            

 

ARTIFICIAL SWEETENERS:-Some individuals use artificial sweeteners to limit their sugar consumption for medical reason, while others do so to avoid calories that might result in weight gain. Example of artificial sweeteners include aspartame, saccharine  and sucralose.Aspertame is 200 times sweeter than sucrose. Saccharin is 400 times sweeter than sucrose and sucralose is 600 times sweeter than sucrose.

Artificial sweeteners are also used as sugar substitute because they do not cause tooth decay.