Carbohydrates

Sugars & Starches & Cellulose

Large and diverse group of Organic Compounds that comprise C, H & O usually in the ratio 1:2:1 (CH₂O)_n

Three classes:

Monosaccharides
Disaccharides
Polysaccharides

Monosaccharides: or simple sugars

Chains or rings containing:

4 Carbons = Tetroses
5 Carbons = Pentoses
6 Carbons = Hexose's

Eg glucose:

or in its ring form:

Disaccharides : double sugars

These form by a dehydration synthesis reaction between two simple sugars:

POLYSACCHARIDES:

These are made up of many simple sugars linked together to form chains.

Their formula is normally reduced to (C₆ H₁₀O₅)_n where n is the number of simple sugar molecules from which they are composed.
The main role of carbohydrates in cells is as a source of chemical energy. Glucose is the most important energy source.

Glycogen is an important energy source in animals.