A Wonderleaf question
Why do lemons taste sour?
a real page from the book
Lemons taste sour because their juice is packed with citric acid. When that acid reaches the tongue, sour-sensing cells notice the extra hydrogen it can give off and send a quick nerve message to the brain: this food is sharp, acidic, and worth paying attention to.
The funny part is that the face you make is protective, not personal taste. Long ago, sourness could warn bodies about unripe fruit or food gone bad, so your mouth makes extra spit and your cheeks pinch in, even when the lemon is safe in lemonade.
Wonder words
- acid
- hydrogen
- receptors
- saliva
Try it out
Taste a tiny lemon lick, then sip water and notice how quickly your mouth makes more saliva.
Read the whole picture book
Watercolour scenes, straight answers, about three minutes cover to cover.
Open the picture bookKeep wondering
- Who invented pizza?
- How is chocolate made?
- How did people keep food fresh before refrigerators?
- Why do fruits taste sweeter when they are ripe?
- Why do we cook food?
- How does food turn into energy?
One more wonder: Why is space so dark?
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