This week's LabZone activity
Sept. 10, 2003
The Taste Test
To find the four different "taste areas" of the tongue you will need a friend to be your "guinea pig," a pipette (dropper), some salt, sugar, vinegar, lemon juice, water and four saucers.
Ask your parents if you can borrow some salt, sugar, vinegar and lemon juice from the kitchen.
Dissolve the sugar in water to make a sweet solution, and do the same with the salt to make a salty one. Partly fill each of your saucers with one of the solutions. You now have a sample of the four different tastes that make up foodsweet, salty, sour (vinegar) and bitter (lemon juice).
Ask your friend to sit down and stick out his tongue! Then fill your pipette with one of the solutions and drip a single drop onto one of the parts of his tongue shown in the diagram beloweither the front, the middle, the back or the side. Ask him which taste he thinks the drop represents and then repeat the test with the other three solutions. Next, test another part of the tongue and carry on until all four areas of the tongue have been tested with all four solutions. Make notes in your Science Notebook of the results.
The center of your tongue detects no particular taste.
From your notes, you should be able to see a pattern forming. Your friend should have been able to taste the sweet solution, for instance, when it was dropped on the center of his tongue. Elsewhere, he may not be able to identify it correctly. The lemon juice, on the other hand, should have been most recognizable when put at the back of his tongue. This is because different parts of the tongue have different kinds of taste buds for tasting various types of food, as you can see from the diagram above. Do your results show the same pattern?
Reprinted with the permission of Benchmark Books from The Marshall Cavendish Science Project Book of the Human Body by Steve Parker. © 1986 by Marshall Cavendish Corporation (http://www.marshallcavendish.com/ ).
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