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Science & TechnologyGreekEnglish

Galactose

/ɡəˈlæktoʊs/noun

A simple sugar that pairs with glucose to form lactose, the sugar of milk.

The Greek roots

γάλα, γάλακτος
gála, gálaktos
milk

Literally: milk sugar

The story of the word

Chemists named it in the mid-nineteenth century after the place they found it, since lactose splits into glucose and this. The Greek for milk also named the sky: the Milky Way was γαλαξίας κύκλος, the milky circle, which is why galaxy and galactose are the same word wearing different clothes. Babies who cannot break galactose down have galactosaemia, one of the conditions newborn heel-prick screening looks for.

How it travelled
Ancient Greek → scientific coinage → English
First recorded
19th century

The same roots elsewhere

Other languages reached for exactly the same Greek pieces.

Same family

galaxylactosegalactosaemia

In a sentence

Lactase splits lactose into glucose and galactose in the small intestine.

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