Carbohydrate

A carbohydrate is an organic compound that consists only of carbon, hydrogen, and oxygen, usually with a hydrogen:oxygen atom ratio of 2:1; in other words, with the empirical formula C_m(H₂O)_n. (Some exceptions exist; for example, deoxyribose, a component of DNA, has the empirical formula C₅H₁₀O₄.) Carbohydrates are not technically hydrates of carbon. Structurally it is more accurate to view them as polyhydroxy aldehydes and ketones.