lactase

American  

[lak-teys, -teyz] / ˈlæk teɪs, -ˌteɪz /

noun

Biochemistry.

1. an enzyme capable of hydrolyzing lactose into glucose and galactose.

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lactase British  

/ ˈlækteɪs, -teɪz /

noun

1. any of a group of enzymes that hydrolyse lactose to glucose and galactose

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lactase Scientific  

/ lăk′tās′ /

1. An enzyme that is found in the small intestine, liver, and kidneys of mammals and catalyzes the breakdown of lactose into galactose and glucose.

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Etymology

Origin of lactase

First recorded in 1890–95; lact- + -ase

Example Sentences

See Examples For:

lactase

The lactase gene determines whether adults can digest milk and affects milk digesting microbes.

From Science Daily ● Dec. 23, 2025

According to Boston Children’s Hospital, lactase is an enzyme that is normally produced in the small intestine, where it breaks down lactose into a form that can be absorbed by the blood.

From Salon ● Dec. 20, 2023

But lactose is not fermentable, so it doesn’t get consumed by the yeast, which does not have the lactase enzyme and therefore is just as lactose-intolerant as any of your cheese-avoidant friends.

From Seattle Times ● Feb. 8, 2023

In a new report, scientists argue that the lactase mutation only became important to survival when Europeans began enduring epidemics and famines.

From New York Times ● Jul. 28, 2022

For example, lactase acts energetically upon ordinary lactose and all other β-galactosides; but not upon any glucoside, mannoside, etc.

From The Chemistry of Plant Life by Thatcher, Roscoe Wilfred