Learning Outcomes
i. Define disaccharides.
ii. Describe the structure and function of different types of disaccharides.
iii. Explain how disaccharides are formed and broken down.
i. What are disaccharides?
Disaccharides are carbohydrates that are made up of two monosaccharides joined together by a glycosidic bond. A glycosidic bond is a covalent bond that is formed between the carbon atom of one monosaccharide and the oxygen atom of another monosaccharide. Disaccharides are broken down into monosaccharides by enzymes called disaccharidases. Disaccharidases are found in the digestive system.
ii. Types of disaccharides
The following are some common disaccharides:
Sucrose (table sugar): Sucrose is made up of glucose and fructose. It is the most common disaccharide and is found in many foods, such as fruits, vegetables, and processed foods.
Lactose (milk sugar): Lactose is made up of glucose and galactose. It is found in milk and other dairy products.
Maltose (malt sugar): Maltose is made up of two glucose molecules. It is formed when starch is broken down by enzymes. Maltose is found in beer and other fermented beverages.
iii. Formation and breakdown of disaccharides
Disaccharides are formed when two monosaccharides are joined together by a glycosidic bond. This process is called dehydration synthesis. Dehydration synthesis is a condensation reaction, which means that a water molecule is removed when the glycosidic bond is formed.
The following is an example of a dehydration synthesis reaction:
Glucose + Fructose -> Sucrose + Water
Disaccharides are broken down into monosaccharides by enzymes called disaccharidases. Disaccharidases are found in the digestive system. For example, the enzyme lactase breaks down lactose into glucose and galactose.
The following is an example of a hydrolysis reaction:
Sucrose + Water -> Glucose + Fructose
Real-world applications of disaccharides
Disaccharides are used in a variety of products and industries. For example, sucrose is used in food products, such as candy, baked goods, and soft drinks. Lactose is used in dairy products, such as milk, cheese, and yogurt. Maltose is used in beer and other fermented beverages. Disaccharides are also used in non-food products, such as cosmetics, pharmaceuticals, and industrial products.
Disaccharides are carbohydrates that are made up of two monosaccharides joined together by a glycosidic bond. Disaccharides are broken down into monosaccharides by enzymes called disaccharidases. Disaccharides are important nutrients that provide energy and are used to synthesize other carbohydrates.
