Carbohydrates

Carbohydrates are defined as polyhydroxy aldehydes or ketones or their derivatives or substances which yields one of these substances on hydrolysis. <br>e.g starch, glucose, fructose, maltose.

Carbohydrates are classified into 4 major groups according to the presence of number of molecules of sugar.
1. Monosaccharides (general formula: (CH2O)n) only contains single molecule of sugar, are simplest form of carbohydrates and cannot be broken down into simpler substances on hydrolysis.
Example : glucose (aldose) ,fructose (ketose).

2. Diasacharides (Cn(H2O)n-1) contains two molecules of simple sugar.. yeild two molecukes of sugar on hydrolydis.
3. Oligosaccharides (two to 10 molecuoes).
E.g stachyose.
4. Polysaccharides ( more than 10 molecules) 
E.g. starch, glycogen.