Tool 04Can opener

Lactase

Opens up milk sugar (lactose).

Workbench

Works on: Lactose, the sugar in milk
Leaves: Glucose and galactose
Made by: The lining of your small intestine.
Works in: The lining of the small intestine.
Sound: POP!

On the bench

Lactase (Can opener)

Lactose 1

Lactose 2

Lactose 3

Lactose 4

Pick a link and cut it with the can opener.

How it works

Lactose is two sugars stuck together: glucose and galactose. You can only absorb them one at a time, so the pair has to be split.

Lactase doesn’t float around in a juice like the pancreas’s tools. It sits on the tips of the microvilli, the brush on the lining of your small intestine, right where the sugars get absorbed. Plenty of adults make less of it than they did as children. Lactose that isn’t split rolls on to the colon, where the crew ferments it.

AnnouncerCan openers were invented about fifty years after cans. Lactase was there first.

Far-out fact

Lactase lives on the lining itself, not in a juice. It splits milk sugar right where it gets absorbed.

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