Lactase

Definition

Lactase is an enzyme produced in the small intestine that breaks down lactose, the sugar found in milk and dairy products, into glucose and galactose for absorption. This process is essential for individuals who consume dairy, as it allows them to digest lactose properly. When lactase is insufficient, it can lead to lactose intolerance, causing digestive discomfort after consuming dairy.

5 Must Know Facts For Your Next Test

1. Lactase production typically decreases after weaning, which is why many adults experience lactose intolerance.
2. In some populations, particularly those with a long history of dairy consumption, lactase persistence allows adults to continue digesting lactose into adulthood.
3. Lactase acts specifically on lactose, breaking it down into its constituent monosaccharides, glucose and galactose, which can then be absorbed into the bloodstream.
4. Lactose intolerance varies widely among individuals; some may tolerate small amounts of lactose while others cannot consume any without discomfort.
5. Lactase supplements are available for individuals who wish to consume dairy but suffer from lactose intolerance.

Review Questions

• How does lactase function in the digestive process, and what happens when its levels are inadequate?
  • Lactase functions by hydrolyzing lactose into glucose and galactose in the small intestine, allowing these simple sugars to be absorbed into the bloodstream. When lactase levels are inadequate, lactose remains undigested in the gut, leading to fermentation by bacteria. This can result in symptoms such as bloating, gas, and diarrhea, collectively known as lactose intolerance.
• Discuss the evolutionary significance of lactase persistence in certain populations and its connection to dietary practices.
  • Lactase persistence refers to the continued production of lactase into adulthood, allowing some populations to digest lactose efficiently. This trait is believed to have evolved in response to dairy farming practices, particularly in cultures where milk was a significant food source. As these populations consumed more dairy products, individuals with lactase persistence had a nutritional advantage, leading to natural selection favoring this trait.
• Evaluate the implications of lactose intolerance on dietary choices and nutritional health for affected individuals.
  • Lactose intolerance has significant implications for dietary choices and nutritional health. Individuals with this condition must often limit or avoid dairy products to prevent discomfort, which can lead to challenges in obtaining sufficient calcium and vitamin D from their diet. Many find alternative sources of these nutrients or choose lactose-free options. Understanding one's lactase levels is crucial for making informed dietary decisions that support overall health while managing symptoms effectively.

Related terms

Lactose: A disaccharide sugar composed of glucose and galactose, primarily found in milk and dairy products.

Lactose Intolerance: A common condition where the body lacks sufficient lactase to digest lactose, leading to symptoms like bloating, gas, and diarrhea after consuming dairy.

Enzyme: A biological catalyst that speeds up chemical reactions in the body, including the breakdown of complex molecules like sugars and proteins.