Lactase

Definition

Lactase is an enzyme produced in the small intestine that catalyzes the hydrolysis of lactose, the sugar found in milk, into glucose and galactose. This enzyme plays a crucial role in the digestion of dairy products, enabling the body to break down lactose into simpler sugars that can be absorbed into the bloodstream.

5 Must Know Facts For Your Next Test

1. Lactase production typically peaks during infancy when milk is a primary source of nutrition, but levels often decrease after weaning in many individuals.
2. The persistence of lactase production into adulthood is due to a genetic adaptation that allows certain populations, especially those with a history of dairy farming, to digest lactose more efficiently.
3. Lactase works by breaking the β-1,4-glycosidic bond between glucose and galactose in lactose, which makes it essential for proper dairy digestion.
4. Individuals with lactase deficiency may experience symptoms like gas, diarrhea, and abdominal pain when consuming lactose-containing foods.
5. Lactase supplements are available over-the-counter for those who are lactose intolerant, helping them to enjoy dairy products without discomfort.

Review Questions

• How does lactase function in the digestion of lactose, and what are the consequences of its deficiency?
  • Lactase functions by catalyzing the hydrolysis of lactose into glucose and galactose, making it easier for the body to absorb these simpler sugars. When lactase is deficient, individuals cannot effectively digest lactose, leading to symptoms such as gas, bloating, and diarrhea. This condition, known as lactose intolerance, can significantly impact dietary choices and nutrition for affected individuals.
• Discuss the evolutionary significance of lactase persistence in certain human populations.
  • Lactase persistence is a fascinating example of human evolution where certain populations developed a genetic adaptation allowing them to continue producing lactase into adulthood. This adaptation likely arose in response to the domestication of dairy animals and the consumption of their milk. As a result, individuals with this trait could utilize milk as a food source, gaining nutritional advantages such as increased caloric intake and hydration, which contributed to survival and reproductive success.
• Evaluate the role of lactase supplements for managing lactose intolerance and their effectiveness compared to dietary modifications.
  • Lactase supplements can be an effective tool for managing lactose intolerance by providing the enzyme necessary to digest lactose when consuming dairy products. While these supplements can alleviate symptoms for many individuals, they do not replace the need for dietary modifications entirely. Some people may still prefer to limit their intake of lactose-containing foods or choose lactose-free alternatives as a more comprehensive approach to managing their condition. Evaluating personal tolerance levels alongside supplement use can lead to better overall management of lactose intolerance.

Related terms

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

Disaccharide: A type of carbohydrate formed by two monosaccharides linked together, which includes sugars like sucrose and lactose.

Lactose Intolerance: A common digestive condition where individuals have insufficient lactase production, leading to difficulty in digesting lactose and resulting in symptoms like bloating and diarrhea.