K-1: The Senses
Our Sense of Taste
What are the basic tastes? Where is information about taste detected in the body?
- All of the senses are connected to the brain.
- Our senses let us know what is going on inside and outside our bodies.
- One of our senses is taste.
- The tongue is covered with taste buds, which contains taste receptors.
- Taste receptors communicate with the brain, which determines the flavors we experience.
- Taste buds detect sweet, sour, salty, bitter and umami (savory) tastes.
Why does chocolate ice cream taste delicious and sour milk taste awful? Scientists believe that taste evolved to help identify potentially nutritious foods and avoid eating things that are harmful.
Taste begins in our mouths, with the chemical receptors that dot our tongues. The tongue’s surface is coated with thousands of small bumps, called papillae. Each papilla holds approximately 10,000 taste buds, which renew themselves about every 10 days, unless they are damaged by infection or smoking. Each taste bud contains 50–150 taste receptor cells.
When you eat, saliva dissolves certain chemicals from the food. The chemicals enter openings in your taste buds and interact with taste receptor cells. The receptor cells send signals to the brain, where they are combined with information from the sense of smell to create what you experience as flavor.
We generally recognize four tastes: sweet, sour, salty and bitter. A fifth taste, umami (savory) occurs when we eat foods with glutamate (like MSG). Bacon, mushrooms and fermented foods, such as cheese and soy sauce, are rich in umami. Beyond allowing us to taste, the tongue can sense pressure, temperature and pain. That’s why we are able to experience certain foods as spicy or minty, and distinguish among different food textures. The sense of smell also contributes to the flavors we experience. Odor qualities, such as floral, fruit, burnt or putrid, shape our food-related sensory experiences.
Some people, called “supertasters,” have more taste buds than average and are highly sensitive to certain tastes. One’s genes can make him or her more sensitive to certain tastes, as well. And over time, many people experience a change in taste sensitivities. That’s why adults sometimes become more tolerant of—and even enjoy—foods, such as broccoli or Brussels spouts, that they avoided as children.
Many older textbooks feature a “map” of the tongue with different regions specialized for particular tastes, such as sweet or sour. This interpretation of the distribution of taste receptors is inaccurate. In fact, receptors for all tastes are distributed throughout the tongue, and even are present in other areas of the mouth.
Procedure: Part 1
Ask students to think about their favorite flavors. Conduct a short class discussion about the foods they mention. Students will probably share foods that are sweet, salty, and sour; but they may describe complex combinations of flavors. Explain that you will create a class “taste” chart. Draw a table on the board and list “Sweet,” “Sour” and “Salty” across the top. Note that the tongue can detect two additional tastes: bitter and umami (savory). Bitter is more common, and can be detected easily, so add a “bitter” column to the table. Then, have students assign the favorite foods they mentioned, or other examples, by adding words or drawings to each category of the class chart.
- Photo © Maryna Pleshkun. Licensed for use.
- Tharp, B., Vu, M., Mock, D., Burnett, C., and Moreno, N. (2015). K-1: The Senses Teacher’s Guide. Baylor College of Medicine, Houston. All rights reserved. ISBN: 978-1-888997-87-3
Your slide tray is being processed.
Funded by the following grant(s)
National Institutes of Health: Blueprint for Neuroscience Education, National Institute on Drug Abuse and Science Education Partnership Award program, Office of the Director, Division of Program Coordination, Planning and Strategic Initiatives, Office of Research Infrastructure Programs.
The Learning Brain: Interactive Inquiry for Teachers and Students
Grant Number: RD25DA033006