Glucose is a sugar with the molecular formula C6H12O6. The name "glucose" (/ˈɡluːkoʊs/) comes from the Greek word γλευκος, meaning "sweet wine, must". The suffix "-ose" is a chemical classifier, denoting a carbohydrate. It is also known as dextrose or grape sugar. With 6 carbon atoms, it is classed as a hexose, a sub-category of monosaccharides. α-D-glucose is one of the 16 aldose stereoisomers. The D-isomer (D-glucose) occurs widely in nature, but the L-isomer (L-glucose) does not.