Which of the following carbohydrates is NOT a disaccharide?

Step-by-step solution

Maltose is a disaccharide composed of two -D-glucose units. Lactose is a disaccharide composed of -D-galactose and -D-glucose units. Sucrose is a disaccharide composed of -D-glucose and -D-fructose units. Mannose is a monosaccharide, specifically an aldohexose, and is a C-2 epimer of glucose. Therefore, mannose is not a disaccharide. Answer: Mannose