Unit 1: Digestion.(Brief Article)

Background Bonus

Foods that make the mouth water appeal to our senses of sight, taste, smell, and touch. Our sense of taste is affected by the number of taste buds we have and how healthy the taste buds are. Not everyone has the same number of taste buds. A study done at the Yale University School of Medicine estimated that 25 percent of the population are nontasters, 50 percent are medium-tasters, and 25 percent are supertasters. Supertasters may have up to 60 times more taste buds packed together on the tongue than do nontasters. Bitter and sweet tastes seem to be the most exaggerated for supertasters. This study may explain why some people think broccoli tastes awful. They may be supertasters, highly sensitive to the bitterness in the vegetable.

Another condition that affects the taste buds is hypogeusia. This condition distorts the senses of smell and taste, and may cause the taste buds to become worn or frayed. Hypogeusia is caused by a deficiency of gustin, a zinc-containing protein found in saliva.

Unit Objectives

Students learn to

* identify the parts of a tooth;

* understand how to care for their teeth;