Disaccharides

Definition

Disaccharides are carbohydrates composed of two monosaccharide molecules linked together. Common examples include sucrose, lactose, and maltose.

5 Must Know Facts For Your Next Test

1. Disaccharides are broken down into monosaccharides by enzymes during digestion for absorption.
2. Sucrose is made of glucose and fructose; lactose is made of glucose and galactose; maltose is made of two glucose molecules.
3. Lactase is the enzyme that breaks down lactose in the small intestine.
4. Inadequate breakdown of disaccharides can lead to digestive problems like lactose intolerance.
5. Disaccharides provide a quick source of energy because they are rapidly digested.

Review Questions

• What monosaccharides compose sucrose, lactose, and maltose?
• Why are disaccharides important for energy metabolism?
• Which enzyme is responsible for breaking down lactose?

Related terms

Monosaccharides: Simple sugars that form the building blocks of disaccharides and polysaccharides.

Polysaccharides: Complex carbohydrates composed of long chains of monosaccharide units.

Enzymes: Biological catalysts that speed up chemical reactions, including the breakdown of disaccharides.