Answer: The chemical composition of carbohydrates gives them several properties that help them to fill so many different roles. Most importantly, they are formed from fundamental units that can then be linked together like Lego bricks to form large and unique molecules. The only biomolecules that are better than carbohydrates at doing this are proteins. The common molecular formula for any carbohydrate is
Cn(H2O)n
The name for these molecules is derived from this ratio: for every carbon atom (carbo-) there is an equal amount of water (-hydrate). Because the combination of carbon, hydrogen, and oxygen can be easily oxidized, but tend not to decompose on their own, carbohydrates have both high energy potential and structural stability. This makes them ideal for fueling biochemical reactions. In fact, oxidation of the carbohydrate glucose is the fundamental chemical reaction that powers all life on earth.