A Science Lesson about Taste...without the Smell!

Here is a fun science lesson about taste. My students really enjoyed this and were very active throughout the lesson.

Taste Testing Without Smell

We all know that some foods taste better than others but what gives us the ability to experience all these unique flavors? This simple experiment shows that there's a lot more to taste than you might have first thought.

What you'll need:

• A small piece of peeled potato
• A small piece of peeled apple (same shape as the potato so you can't tell the difference)

  Instructions:

1. Close your eyes and mix up the piece of potato and the piece of apple so you don't know which is which.
2. Hold your nose and eat each piece, can you tell the difference?

 What's happening?

Holding your nose while tasting the potato and apple makes it hard to tell the difference between the two. Your nose and mouth are connected through the same airway which means that you taste and smell foods at the same time. Your sense of taste can recognize salty, sweet, bitter and sour but when you combine this with your sense of smell you can recognize many other individual 'tastes'. Take away your smell (and sight) and you limit your brains ability to tell the difference between certain foods.

No Saliva, No Taste?

 In order for food to have taste, chemicals from the food must first dissolve in saliva. Once dissolved, the chemicals can be detected by receptors on taste buds. Therefore, if there is no saliva, you should not be able to taste anything. To test this theory, dry your tongue with a clean paper towel. Once your tongue is dry, try tasting a few samples of salt, sugar or other dry foods. Rinse your mouth and dry your tongue after each test.

Materials:

• Food items - sugar, salt, crackers and other dry food
• Clean paper towels
• Water (for rinsing in between tests)

Have you ever thought about why foods taste different? It's really quite amazing. Your tongue and the roof of your mouth are covered with thousands of tiny taste buds. When you eat something, the saliva in your mouth helps break down your food. This causes the receptor cells located in your tastes buds to send messages through sensory nerves to your brain. Your brain then tells you what flavors you are tasting.

Taste buds probably play the most important part in helping you enjoy the many flavors of food. Your taste buds can recognize four basic kinds of tastes: sweet, salty, sour, and bitter. The salty/sweet taste buds are located near the front of your tongue; the sour taste buds line the sides of your tongue; and the bitter taste buds are found at the very back of your tongue.

Everyone's tastes are different. In fact, your tastes will change as you get older. When you were a baby, you had taste buds, not only on your tongue, but on the sides and roof of your mouth. This means you were very sensitive to different foods. As you grew, the taste buds began to disappear from the sides and roof of your mouth, leaving taste buds mostly on your tongue. As you get older, your taste buds will become even less sensitive, so you will be more likely to eat foods that you thought were too strong as a child.

What if you could not taste anything? Things like medications, smoking, not getting enough of the right vitamins, injury to the head, brain tumors, chemical exposure, and the effects of radiation can cause taste disorders.

ü  We have almost 10,000 taste buds inside our mouths, even on the roofs of our mouths.

ü  Insects have the most highly developed sense of taste. They have taste organs on their feet, antennae, and mouthparts.

ü  Fish can taste with their fins and tail as well as their mouth.

ü  In general, girls have more taste buds than boys.

ü  Taste is the weakest of the five senses.

ü  Dogs have taste buds. Most of their taste buds are located at the tip of the tongue. However, they only have about 17% as many taste buds as we do. (That means that they only have about 1,700 taste buds.

GOT TASTE?

1.      Of the five senses, which is the weakest sense?

a.    Taste

b.    Touch

c.    Smell

d.    Hearing

2.    When you eat, what helps break down your food?

a.    Saliva

b.    Teeth

c.    Time

d.    Sulfuric Acid

3.    Does your tongue have different taste buds? If yes, what are they?

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4.    Which of the following is not one of the four basic tastes?

a.    Salty

b.    Bitter

c.    Nasty

d.    Sweet

5.    Which two senses are directly connected?

_____________________________________________________________________

6.    Do animals have taste buds?     Yes              No

7.    What is YOUR favorite taste? Explain your answer

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  8.     What is the value of having taste buds? Explain your answer

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