Which of the following are examples of common monosaccharides?

Monosaccharides are the simplest form of carbohydrates, consisting of single sugar units that cannot be hydrolyzed into simpler sugars. Glucose, galactose, and fructose are all examples of monosaccharides because they each contain a single sugar unit and serve fundamental roles in energy metabolism and cellular functions.

Glucose, for instance, is a primary energy source for cells and is critical in cellular respiration. Galactose is part of lactose, the sugar found in milk, and is used by the body to synthesize molecules like glycoproteins. Fructose is found in many fruits and is another important energy source that is metabolized differently from glucose.

In contrast, other options include substances that are not monosaccharides. For example, starch and cellulose are polysaccharides, made up of long chains of glucose units and serve as energy storage or structural components in plants. Sucrose and maltose are disaccharides, consisting of two monosaccharide units. Glycerol is also not a sugar; it is a three-carbon alcohol that forms part of lipids. This distinction helps clarify why the choice highlighting glucose, galactose, and fructose accurately reflects common examples of monosaccharides.