Monosaccharides Disaccharides & Polysaccharides Carbohydrates

 

In contrast to protein and lipid carbohydrate are mainly utilise to provide as a source of energy to run life activities.

Carbohydrates are present in very simple monosaccharides to complex form as polysaccharides and glycoconjugate.

Monosaccharides:- 

It is the simplest form of carbohydrate aldehyde and ketone with two or more hydroxyl  group. The backbone is made up of 3 to 6 carbon with hydroxyl group attach it.

The simplest sugar is named by the sugar of carbon present in each molecule triose with three carbon such as glyceraldehyde,tetraose with four carbon such as therose,pentose with 5 carbon such as ribose,hexane with 6 carbon such as glycose.

Properties of monosaccharides:- 

• Hemi acetal or hemiketal formation

Linkage between aldehyde and alcohol group called as hemiacetal linkage.

In this diagram we have so dextro rotatory structure of glucose that will change in fisher formula during the hemiacetal formation and we have show the fisher formula in cyclisation form i.e Haworth Formula

Linkage between keto and alcohol group called as hemiketal linkage.

Optical activity:- 

The ability of sugar to rotate plane polarised light

Right means dexo rotatory

left mean levorotatory

L and D forms :-  

The sugar in the fisher projection the OH group have highest number chilarity centre, if left it mean L sugar if right it mean D sugar.

D sugar means compound that have last asymmetrical carbon in the same orientation.

Epimers:-  

Configuration of OH and H carbon 2,3 and 4 of glucose.

Mutarotation :- 

The change in optical rotation either from the glucose is allowed to stand in solution is called as Mutarotation.

Note:- Same structure of D glucose and it's cyclisation form

Anomerism :- 

Carbohydrate isomerism in which isomerism differ configuration at hemiacetal carbon is called as anomerism.

The two form of diosteromeric and differ from each other in absolute configuration at only one of many chiral centre called as EPIMERS.

α forms so that bulki OH lies at axial position at carbon is 1 where as no bulki group comes at axial position β form.

so we can say that β from so most stable and it exist in more amount in the solution.

α-glucose:- 36%

β-glucose:- 64%