Monosaccharides 

                   ⮚Monosaccharides are the simplest form of Carbohydrates. These monosaccharides are the simple sugar having the molecular formula Cn(H20)n and cannot be hydrolyzed further. 
              ⮚These monosaccharides are linked by special type of covalent bond called glycosidic bond. Two monosaccharide monomers are linked to form the Disaccharide. Two to ten monosaccharide monomers are linked to form the Oligosaccharide. Several monomers are linked to form the Polysaccharides. 
               ⮚Based on the number of carbon atom the monosaccharides are further divide into Trioses, Tetroses, Pentoses, Hexoses, Heptoses.
               ⮚Based on the function group it divided into aldoses (Ex: Glyceraldehyde, Glucose) and ketoses (Ex: dihydroxy acetone, fructose).
               ⮚Examples for the monosaccharides are Glucose, Fructose and Galactose.


Glucose 


           ⮚Glucose is one of the most common monosaccharide that is abundant in nature. In 1747 Andreas Marg Graff was first isolated. It is sweet in taste and crystalline in structure and are soluble in water. 
         ⮚Glucose is composed of 6 carbon molecules. It can be broken down in Glycolysis cycle. It provides energy and helps in cellular respiration. If cell doesn’t need energy it will be stored in liver and muscles. 
         ⮚The molecular structure of Glucose is C6H12O6. It can exist in both straight and chain structure. Glucose is a reducing sugar.

Fructose


          ⮚It was discovered by French chemist name Augustin in 1847. Fructose has higher solubility then others. 
          ⮚It is also known as fruit sugar is a simple ketonic molecules found in many plants. Fructose contains ketone as the functional group.
          ⮚Fructose can combine with Glucose by glycosidic bond to form a Disaccharide called Sucrose.

Galactose 

          ⮚It is commonly called as milk sugar. Galactose exist in both cyclic and open chain form. Galactose is widely found in dairy products, Avogadro’s, Sugars, Beets. 
          ⮚Galactose is also synthesized by the body. Where it forms of Glycolipids &Glycoproteins in several tissues. Galactose combine with glucose to from a disaccharide called lactose.

Reactions of monosaccharides 


Tautomerization: 


           ➣It is the process of shifting a hydrogen atom from One carbon atom to another to produce enediols is known as Tautomerization. 
           ➣Glucose Kept in alkaline solution for several hours, it undergoes isomerization to form D-fructose and D-Mannose.

Oxidation: 


           ➣Depending on the oxidizing agent used, the terminal aldehyde or keto or alcohol groups may be oxidized.
           ➢Oxidation of aldehyde results in the form of Gluconic acid.
                    CHO →  COOH

Reduction: 

 
           When treated with reducing agents such as amalgam, sodium the aldehyde or keto group of monosaccharides is reduced to alcohol. 

Dehydration: 

        When treated with concentrated H2SO4 monosaccharides undergo dehydration with an elimination of 3H20 molecules.