Body & HealthFact

The onion isn't crying. It's shooting.

An intact onion doesn't sting. Only your knife breaks cell walls, letting two separately stored substances meet: an enzyme and a sulphur compound. Within seconds they form the gas syn-propanethial-S-oxide. It reaches your cornea, irritates nerve endings there, and your tear gland flushes with fluid. It's the plant's defence against being eaten.

Useful: Cold slows the reaction: a chilled onion releases less gas.

Source: en.wikipedia.org

Auge Chemie Kueche

Difficulty:

Related cards

How baking powder puffs up a cake, and why baking soda alone can't.Baking powder is sodium bicarbonate plus a dry acid plus a little starch against moisture. As soon …
Bread crust, steak and coffee owe their flavour to the same reaction.From roughly 140 to 165 °C, amino acids react with sugars into hundreds of new flavour and colour …
Each eye is missing a patch of image, and you never notice.Where the optic nerve leaves the retina there are no light-sensing cells. This blind spot sits …
You're blind for hours every day without noticing.Your eyes jump about 3 times a second in rapid movements called saccades. During each jump, lasting …
After 40 your arms seem to get too short.Over the years the eye's lens loses elasticity and hardens, and the ciliary muscle weakens too. …
Roughly one man in twelve mixes up red and green.Red-green colour blindness affects about 8 percent of men and around 0.5 percent of women of …
At night you only see faint stars if you look away.Your retina carries about 120 million rods for dim light and some 6 million cones for colour and …
Diamond and pencil lead are made of exactly the same stuff.Both are pure carbon. In diamond, every atom bonds tightly to four neighbours in a …

Keep reading

This card belongs to the topic Body & Health. Every card is short, cites a source and can be saved – due ones come back by themselves later.

About Doomlearn · Projects · Legal notice · Privacy · Terms