Glucose, fructose, and galactose are examples of what?

• A. Monosaccharides
• B. Disaccharides
• C. Polysaccharides
• D. Oligosaccharides

Answer: (A)

Simple sugars are the building blocks of carbohydrates, and glucose, fructose, and galactose are all single sugar units. They are monosaccharides because each is a single sugar molecule that cannot be broken down into smaller carbohydrate units without breaking chemical bonds. They’re absorbed directly in the gut and serve as the basic units from which more complex carbohydrates are formed. All three are hexoses, containing six carbons, with glucose and galactose classified as aldoses and fructose as a ketose. In contrast, disaccharides are pairs of monosaccharides (like sucrose or lactose), polysaccharides are long chains of many monosaccharides (like starch or cellulose), and oligosaccharides are short chains of a few monosaccharides.