Carbohydrates are known as the main energy source for living things. The composition of carbohydrates is made of the elements carbon, hydrogen, and oxygen.
Closed rings are the most common basic structure of carbohydrates. Glucose is an example of a single closed ring carbohydrate known as a monosaccharide.
Two closed-ring sugar molecules can be linked together into structures called a disaccharides.
When three or more closed-ring sugars are linked together they are called a polysaccharide. Food starch is an example of a polysaccharide.
This image shows the structure of a five carbon ringed sugar molecule.