Monosaccharides, the simplest sugars, may be named according to the number of carbon atoms in each molecule of the sugar: pentose is a five-carbon monosaccharide, and hexose is a six-carbon monosaccharide. Aldehyde monosaccharides may be called aldoses; ketone monosaccharides may be called ketoses.
Larger sugars such as disaccharides and polysaccharides can be named to reflect their qualities. Lactose, a disaccharide found in milk, gets its name from the Latin word for milk combined with the sugar suffix; its name means "milk sugar". The polysaccharide that makes up plant starch is named amylose, or "starch sugar"; see amyl#Etymology.
There are these theories about the origin of the -ose suffix:-
- Extracted from glucose, an important hexose whose name came from Greek γλυκύς = "sweet".
- Extracted from sucrose, whose name came from Latin sucrum = "sugar" plus the common Latin adjective-forming suffix -ōsus; Latin sucrosus would mean "sugary".