lactase

noun

lac·​tase ˈlak-ˌtās How to pronounce lactase (audio)
-ˌtāz
: an enzyme that hydrolyzes beta-galactosides (such as lactose) and occurs especially in the intestines of young mammals and in yeasts

Example Sentences

Recent Examples on the Web Additionally, there is a strong correlation between pastoralism and lactase persistence. Razib Khan, Discover Magazine, 8 Sep. 2011 Drinking a domestic animal's milk must have given these populations a serious evolutionary advantage in order for the lactase-keeping trait to spread so well. Elizabeth Preston, Discover Magazine, 21 June 2011 If your body doesn’t produce enough lactase, the enzyme that breaks down the sugar in dairy, drinking a gallon of milk is probably going to lead to bloating, nausea, and some serious farts, at minimum. Ali Francis, Bon Appétit, 21 Sep. 2022 The study also can’t account for the separate development of lactase-persistence alleles in other areas of the world, most notably in Africa, another continent where early evidence of milk consumption has been found. Haley Weiss, The Atlantic, 27 July 2022 What’s more, studies of ancient human DNA have shown that the genetic mutation that enabled European lactase persistence doesn’t look like something that conferred a marginal nutritional advantage. Brian Handwerk, Smithsonian Magazine, 27 July 2022 Celiac disease and small intestinal bacterial overgrowth are malabsorption syndromes that can sometimes mimic pure lactase deficiency. Dr. Keith Roach, oregonlive, 19 May 2022 In drinking a full gallon of milk, most people burn through their available lactase and then become lactose intolerant during the challenge.... Peter Weber, The Week, 1 Oct. 2018 This happens if the small intestine doesn't make enough lactase, the enzyme that helps with dairy digestion by breaking down lactose. Melissa Matthews, SELF, 5 Jan. 2021 See More

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.

Word History

Etymology

International Scientific Vocabulary

First Known Use

1891, in the meaning defined above

Time Traveler
The first known use of lactase was in 1891

Dictionary Entries Near lactase

Cite this Entry

“Lactase.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/lactase. Accessed 27 Mar. 2023.

Kids Definition

lactase

noun
lac·​tase ˈlak-ˌtās How to pronounce lactase (audio)
: an enzyme that breaks down lactose and related compounds and occurs especially in the intestines of young mammals and in yeasts

Medical Definition

lactase

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

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