In the context of nutrition, what are disaccharides?

Disaccharides are sugars that consist of two monosaccharides joined together by a glycosidic bond. This means that they are the result of a dehydration synthesis reaction between two simple sugars. Common examples of disaccharides include sucrose (which is composed of glucose and fructose), lactose (glucose and galactose), and maltose (two glucose molecules). Understanding disaccharides is important in nutrition because they are a significant source of energy in the diet and can impact blood sugar levels.

The other options describe different types of macromolecules. Complex carbohydrates consist of long chains of monosaccharides and include polysaccharides, which are not just two units but many. Fats typically consist of glycerol and three fatty acids, not just two, and proteins are made up of long chains of amino acids, not just two. Thus, the definition of disaccharides as sugars made up of two monosaccharides is accurate and aligns with fundamental nutritional science.