What are the main functions of Carbohydrates?

Carbohydrates are used as fuel by our bodies. Digestion breaks down starch and sugars, by hydrolysis, into monosaccharides which can be absorbed by the small intestine. Once in the blood, this blood sugar (glucose) can be stored as glycogen in the liver or transported to cells by the blood. In cells, glucose acts as a chemical fuel that can be converted by mitochondria (the powerhouses / glucose burners / ATP generators) into ATP. ATP or adenosine triphosphate is the energy currency of cells and powers activities in cells that require energy.