Nomenclature of monosaccharides

The IUPAC system gives every monosaccharide a systematic name built from two pieces of information: whether its single carbonyl group is an aldehyde or a ketone, and how many carbon atoms the molecule contains. The generic root name for any monosaccharide is 'glycose'. A monosaccharide whose carbonyl group is aldehydic (-CHO) is called an aldose; one whose carbonyl group is ketonic (C=O flanked by two carbons) is called a ketose. This aldose/ketose root is then combined with a carbon-count prefix taken from the general hydrocarbon-chain naming pattern (tri-, tetr-, pent-, hex-, hept-, and so on) followed by '-ose'. Glucose, molecular formula C6H12O6, has an aldehydic carbonyl and six carbons, so it is named an aldohexose. Fructose, also C6H12O6, has a ketonic carbonyl and six carbons, so it is named a ketohexose -- the two are constitution …