Lactose

Definition

Lactose is a disaccharide sugar composed of two monosaccharides, glucose and galactose, and is primarily found in milk and dairy products. It serves as an important energy source in the diet, particularly for infants who consume breast milk. Lactose plays a role in digestion and metabolism, highlighting its connection to carbohydrates and how they function in the body.

5 Must Know Facts For Your Next Test

1. Lactose is found mainly in milk from mammals, making it a key component of human nutrition during infancy.
2. About 65% of the world's adult population experiences some level of lactose intolerance due to decreased production of lactase after weaning.
3. In lactose intolerance, undigested lactose in the gut can cause symptoms like bloating, gas, and diarrhea due to fermentation by gut bacteria.
4. Lactose can be broken down into its constituent sugars, glucose and galactose, which are then utilized by cells for energy production.
5. Lactose is also used in various food products and pharmaceuticals as a filler or stabilizer due to its non-reactive properties.

Review Questions

• What role does lactase play in the digestion of lactose and how does its deficiency affect individuals?
  • Lactase is the enzyme responsible for breaking down lactose into glucose and galactose in the small intestine. When an individual has a deficiency of lactase, they are unable to digest lactose effectively, leading to symptoms associated with lactose intolerance. This results in undigested lactose reaching the colon, where it is fermented by bacteria, causing discomfort such as bloating and gas.
• Discuss the implications of lactose intolerance on dietary choices and nutritional health.
  • Lactose intolerance can significantly impact dietary choices as individuals may need to avoid or limit dairy products to prevent uncomfortable symptoms. This can lead to nutritional deficiencies if alternatives are not provided; for instance, calcium and vitamin D levels may drop if dairy sources are excluded. Many people turn to lactose-free products or other calcium-rich foods to maintain their nutrient intake while managing their condition.
• Evaluate how understanding lactose metabolism can influence food product development for those with dietary restrictions.
  • Understanding lactose metabolism allows food developers to create products that cater to individuals with lactose intolerance or dietary restrictions. By incorporating lactase enzymes into dairy products, manufacturers can produce lactose-free options that retain taste and nutritional value while minimizing digestive discomfort. This approach not only meets consumer demand but also expands market opportunities for healthier options that accommodate diverse dietary needs.

Related terms

Lactase: An enzyme produced in the small intestine that breaks down lactose into glucose and galactose, facilitating its absorption into the bloodstream.

Galactose:

A monosaccharide that combines with glucose to form lactose; it is important for cellular metabolism and can be converted into glucose by the body.

Disaccharide: A type of carbohydrate formed by two monosaccharides linked together, such as lactose, sucrose, and maltose.