Lactase

Definition

Lactase is an enzyme produced in the small intestine that breaks down lactose, a sugar found in milk and dairy products, into glucose and galactose, which can then be absorbed into the bloodstream. This enzyme is crucial for individuals who consume dairy, as it allows for the proper digestion of lactose. A deficiency in lactase can lead to lactose intolerance, which causes digestive discomfort when consuming dairy.

5 Must Know Facts For Your Next Test

1. Lactase production is typically highest during infancy when milk is the primary source of nutrition, but levels often decrease after weaning.
2. In many populations around the world, lactase persistence into adulthood is rare, resulting in higher rates of lactose intolerance.
3. Lactase works best at a neutral pH, making it most effective in the small intestine where it can function optimally.
4. People with lactose intolerance can often tolerate small amounts of lactose or dairy products that are lower in lactose content, like hard cheeses or yogurt.
5. There are lactase supplements available that can help individuals with lactose intolerance digest dairy products more comfortably.

Review Questions

• What role does lactase play in the digestive process and how does its deficiency affect individuals?
  • Lactase is essential for breaking down lactose into glucose and galactose during digestion. When there is a deficiency of lactase, individuals cannot effectively digest lactose, leading to symptoms of lactose intolerance such as bloating, gas, and diarrhea. Understanding this relationship helps emphasize the importance of this enzyme for those consuming dairy products regularly.
• Discuss how genetic factors influence lactase production and the prevalence of lactose intolerance among different populations.
  • Genetic variations determine lactase persistence or non-persistence among populations. In cultures with a long history of dairy consumption, such as Northern Europeans, many individuals retain high levels of lactase into adulthood. In contrast, populations with less dairy consumption typically experience a decline in lactase production after weaning, resulting in higher instances of lactose intolerance. This illustrates how dietary habits can shape genetic evolution over time.
• Evaluate the implications of lactase deficiency on nutritional choices and health for individuals with lactose intolerance.
  • Lactase deficiency significantly impacts nutritional choices for those affected by lactose intolerance. They must often avoid dairy products or choose lactose-free alternatives to prevent discomfort. This avoidance can lead to challenges in obtaining adequate calcium and vitamin D if not carefully managed. Therefore, understanding lactase's role is crucial for individuals to make informed dietary decisions that maintain their health while managing their condition.

Related terms

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

Enzyme: Biological catalysts that accelerate chemical reactions in the body, including those involved in digestion.

Lactose Intolerance: A common condition resulting from a deficiency of lactase, leading to difficulty digesting lactose and causing gastrointestinal symptoms.