The primary sugar present in milk is lactose. Here are the details regarding its composition, linkage, and function:
Composition
- Lactose is a disaccharide composed of two monosaccharides:
- Glucose: A simple sugar that serves as an energy source.
- Galactose: A sugar that is part of various biomolecules and plays important roles in metabolism.
- The molecular formula of lactose is C₁₂H₂₂O₁₁.
Linkage
- The linkage in lactose is formed through a β-1,4-glycosidic bond. In this bond, the anomeric carbon of the galactose (C1) is linked to the hydroxyl group (C4) of glucose. This type of linkage is crucial for the structure and digestibility of lactose.
Function
- Energy Source: Lactose is a significant source of energy, especially for infants. It provides glucose through hydrolysis during digestion, making it an important caloric source.
- Calcium Absorption: Lactose facilitates the absorption of calcium and other minerals, which is essential for bone health, particularly in growing children.
- Prebiotic Effects: In some cases, lactose can promote the growth of beneficial gut bacteria, contributing to healthy digestion.
In summary, lactose plays several vital roles in nutrition, particularly in the dietary needs of infants and young animals, while also contributing to the absorption of essential nutrients.