Which carbohydrate is classified as a monosaccharide?

Glucose is classified as a monosaccharide because it consists of a single sugar molecule, which makes it the simplest form of carbohydrate. Monosaccharides are the building blocks of carbohydrates and typically have the chemical formula (CH₂O)n, where n can range from 3 to 7. Glucose is a six-carbon sugar (hexose) and plays a crucial role in providing energy for cellular processes.

In contrast, sucrose, lactose, and maltose are classified as disaccharides, as they are composed of two monosaccharide units linked together. Sucrose is formed from glucose and fructose, lactose consists of glucose and galactose, and maltose is made up of two glucose molecules. Therefore, the correct identification of glucose as a monosaccharide highlights its fundamental role in carbohydrate metabolism and energy production in organisms.