lactase

noun
lac·​tase | \ ˈlak-ˌtās How to pronounce lactase (audio) , -ˌtāz\

Definition of lactase

: an enzyme that hydrolyzes beta-galactosides (such as lactose) and occurs especially in the intestines of young mammals and in yeasts

Examples of lactase in a Sentence

Recent Examples on the Web

More than 90% of China’s population is deficient in lactase, the enzyme that breaks down the milk sugar lactose in the gut, per a 1984 study. Eamon Barrett, Fortune, "How Oatly Plans to Quench China’s Thirst for Milk," 23 July 2019 June 12, 201700:59 Lactose is a naturally occurring sugar in milk that can cause digestive issues like gas and bloating for people who lack the enzyme (lactase) to digest it. NBC News, "Dr. Fernstrom: What's the best milk alternative for YOUR lifestyle?," 17 July 2019 The spread of that culture had the effect of spreading the lactase persistence gene. Quanta Magazine, "Finding the Actions That Alter Evolution," 5 Jan. 2017 Drinking milk after your lactase gene is turned off is no fun. Bob Gathany, AL.com, "Up in the air at the Huntsville Community Kite Festival," 4 Mar. 2018 Famous enzymes include lactase, which breaks down milk sugars in those who are lactose tolerant. Ian Haydon, Scientific American, "Enzymes versus Nerve Agents: Designing Antidotes for Chemical Weapons," 11 Apr. 2017 However, once the infants are weaned, the lactase-producing gene is turned off. Bob Gathany, AL.com, "Up in the air at the Huntsville Community Kite Festival," 4 Mar. 2018 During fermentation, bacteria break down milk sugars including lactase, turning them into acids and easing digestion for those with lactose intolerance. Brian Handwerk, Smithsonian, "How Cheese, Wheat and Alcohol Shaped Human Evolution," 7 May 2016 To digest lactose requires an enzyme called lactase, which infants of all mammals produce. Bob Gathany, AL.com, "Up in the air at the Huntsville Community Kite Festival," 4 Mar. 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'lactase.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

See More

First Known Use of lactase

1891, in the meaning defined above

History and Etymology for lactase

International Scientific Vocabulary

Keep scrolling for more

Learn More about lactase

Statistics for lactase

Look-up Popularity

Time Traveler for lactase

The first known use of lactase was in 1891

See more words from the same year

Keep scrolling for more

More Definitions for lactase

lactase

noun
lac·​tase | \ ˈlak-ˌtās, -ˌtāz How to pronounce lactase (audio) \

Medical Definition of lactase

: an enzyme that hydrolyzes especially lactose to glucose and galactose and occurs especially in the intestines of young mammals and in yeasts

More from Merriam-Webster on lactase

Rhyming Dictionary: Words that rhyme with lactase

Britannica.com: Encyclopedia article about lactase

Comments on lactase

What made you want to look up lactase? Please tell us where you read or heard it (including the quote, if possible).

WORD OF THE DAY

to fake an opponent out of position

Get Word of the Day daily email!

Test Your Vocabulary

Where in the World? A Quiz

  • peter bruegel tower of babel painting
  • What language does pajama come from?
Spell It

Can you spell these 10 commonly misspelled words?

TAKE THE QUIZ
Citation

Test Your Knowledge - and learn some interesting things along the way.

TAKE THE QUIZ
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!