Monosaccarides

 TOPIC# 5        TYPES OF CARBOHYDRATES(ON BASIS OF CARBON ATOMS)

INTRODUCTION:

There are three types of carbohydrates on basis of carbon atoms;

1-MONOSACCHARIDES:

MONO stands for one and SACCHARIDES stands for sugars.

PROPERTIES:

They are simplest sugars.

It cannot hydrolyzed further into simpler units by addition of water .

They are primary source of energy.

They are sweeter in nature,

They are white crystalline powders .

They are easily soluble in water because they have hydroxyl group.

There empirical formula is (CH2O)n having same hydrogen and oxygen ratio as water(2:1).

They have 3-7 carbon atoms.

They have keto and aldehyde group.

Their names end with -ose they are named as trioses,tetroses,pentoses,hexoses and hectoses.

They are present in linear structure but they form ring structure in water and ring contain carbon atoms to which hydroxyl groups are attached.

Those carbon having hydroxyl group on upward side are called as BETA CARBON.

And those carbon  having hydroxyl group on downward side are called as ALPHA CARBON.

Simplest monosaccharides having 3 carbon called as gluceraldehyde.

Tetrose having 4 carbon is erytrose.

Pentoses having 5 carbon is Ribose having aldehyde group and ribulose having ketonic form.

Hexoses having 6 carbon are glucose,galactose which are aldehydic form while fructose is ketonic form.

SImplest carbohydrate or complex monosaccharides having 7 carbon called as soda hectose.

EXAMPLES:

TRIOSES      GLUCERALDEHYDE

TETROSES  ERYTHROSE

PENTOSES RIBOSE AND RIBULOSE

HEXOSES  GLUCOSE,GALACTOSE AND FRUCTOSE.

The glucose,galactose and fructose are steriosomers but still having different spaitial arangement.