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. This process is crucial for the digestion of dairy foods, allowing individuals to absorb these simple sugars into the bloodstream for energy. When lactase levels are insufficient, it can lead to lactose intolerance, causing digestive discomfort after consuming dairy products.

5 Must Know Facts For Your Next Test

1. Lactase is produced by the enterocytes in the lining of the small intestine and its production can decrease with age.
2. The activity of lactase is highest during infancy, enabling babies to digest breast milk effectively.
3. Lactose intolerance varies among populations, with higher prevalence in certain ethnic groups due to genetic factors affecting lactase production.
4. In addition to dairy, some processed foods and medications may contain lactose, which can affect individuals with lactose intolerance.
5. Some individuals with lactose intolerance may still tolerate small amounts of lactose or fermented dairy products like yogurt due to lower lactose levels.

Review Questions

• How does lactase function in the digestion process, and what happens when lactase levels are low?
  • Lactase functions by breaking down lactose into glucose and galactose, which can then be absorbed by the intestines. When lactase levels are low, undigested lactose remains in the gut, leading to symptoms of lactose intolerance such as bloating, gas, and diarrhea. This highlights the importance of lactase for proper dairy digestion and nutrient absorption.
• Discuss how genetic variations affect lactase production in different populations around the world.
  • Genetic variations significantly influence lactase production among different populations. In populations with a long history of dairy consumption, such as those in Northern Europe, there tends to be a higher prevalence of lactase persistence into adulthood. Conversely, populations with less reliance on dairy products typically show higher rates of lactose intolerance due to reduced lactase gene expression after weaning.
• Evaluate the implications of lactase deficiency on nutrition and lifestyle choices for affected individuals.
  • Lactase deficiency can greatly impact an individual's dietary choices and overall nutrition. Those with lactose intolerance may avoid dairy products to prevent gastrointestinal discomfort, which could lead to deficiencies in calcium and other nutrients typically obtained from dairy. Consequently, individuals may need to seek alternative sources of these nutrients or consider lactase supplements to manage their condition while maintaining a balanced diet.

Related terms

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

Enzyme: A protein that acts as a catalyst to accelerate biochemical reactions in the body, including digestion.

Lactose Intolerance: A condition resulting from the insufficient production of lactase, leading to difficulty digesting lactose and causing gastrointestinal symptoms.