What is the molecular formula of glucose?

The molecular formula of glucose is C6H12O6. It shows that each glucose molecule contains six carbon atoms, twelve hydrogen atoms, and six oxygen atoms.

Glucose is a monosaccharide, or single-unit sugar, and specifically an aldohexose because it has six carbon atoms and an aldehyde group in its open-chain form. Plants make it from carbon dioxide and water during photosynthesis. Cells then break it down to produce ATP, the main usable energy currency of biology. Plants store excess glucose mainly as starch, while animals store it as glycogen.

The same formula can describe different structural arrangements. Fructose also has the formula C6H12O6, but its atoms are connected differently, making it a structural isomer rather than glucose. Glucose is commonly called dextrose, especially on food labels and in medical contexts. It was first isolated from raisins in 1747 by German chemist Andreas Marggraf, and the name glucose was later coined by Jean-Baptiste Dumas in 1838.