Carbohydrates, like all organic molecules, always contain carbon (C) and hydrogen (H) atoms. Carbohydrate molecules are characterized by the presence of the atomic grouping H-C-OH, in which the ratio of hydrogen atoms (H) to oxygen atoms (O) is approximately 2:1. Because this ratio is the same as the ratio in water, the name “hydrates of carbon” seems appropriate. Carbohydrates first and foremost function for quick, short-term energy storage in all organisms, including humans.
