Glucose is a sugar with the molecular formula C6H12O6. The name 'glucose'comes from the Greek word ??e????, 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. a-D-glucose is one of the 16 aldose stereoisomers. The D-isomer occurs widely in nature, but the L-isomer does not. Glucose is made during photosynthesis from water and carbon dioxide, using energy from sunlight.