lactase

/'læki/

Thân thiện

A student adds lactase drops to a glass of milk.

Definition

1. Noun:
   • An enzyme: Lactase is a specific type of enzyme produced in the small intestine. Its primary biological function is to break down lactose, a sugar found in milk and dairy products, into the simpler sugars glucose and galactose, which the body can then absorb.

Usage

• Lactase is essential for the proper digestion of dairy products.
• A deficiency in lactase production leads to lactose intolerance.
• The enzyme lactase acts on its substrate, lactose.

Examples

• Noun:
  • Infants produce high levels of lactase to digest their mother's milk.
  • People with lactose intolerance often take lactase supplements before consuming dairy.
  • The activity of the lactase enzyme decreases in many adults.

Advanced Usage

• "Lactase persistence": A genetic trait in some human populations where the production of the lactase enzyme continues into adulthood, allowing for the digestion of milk.
  • Lactase persistence is common in populations with a long history of dairy farming.

Variants and Related Words

• Lactose (n): The sugar in milk that lactase breaks down.
  • Lactose is a disaccharide composed of glucose and galactose.
• Lactase-phlorizin hydrolase (n): The full scientific name for the lactase enzyme.
• Lactaid® (n): A common brand name for lactase enzyme supplements.

Synonyms

• Beta-galactosidase: The broader enzymatic category to which lactase belongs, though "beta-galactosidase" can refer to enzymes from various sources, not just human intestinal lactase.

Notes on Meaning

• The term lactase refers strictly to the enzyme itself. It is not used to describe the condition of lactose intolerance or the sugar lactose. Its meaning is highly specific within biochemistry, biology, and nutrition.

Học thuật

Noun

1. any of a group of enzymes (trade name Lactaid) that hydrolyze lactose to glucose and galactose

Từ đồng nghĩa

• lactaid