Fructose is a ______ and has ______ carbons.

• A. monosaccharide; 5
• B. monosaccharide; 6
• C. disaccharide; 6
• D. polysaccharide; 6

Answer: (B)

Fructose is a simple sugar that exists as a single sugar unit, which makes it a monosaccharide. It has six carbon atoms in its backbone, so it belongs to the hexose family. Among sugars, this places fructose alongside glucose and galactose as hexose monosaccharides. It’s not a disaccharide because it isn’t composed of two monosaccharide units, and it isn’t a polysaccharide because it isn’t a long chain of sugars. Fructose is specifically a ketohexose, meaning its carbonyl group is a ketone, which is a helpful detail but not required for this question. So describing fructose as a monosaccharide with six carbons correctly identifies its basic classification.