The Investigation Of The Taste Buds

Ola Jean McGehee               Yale Elementary
                               7025 So.Princeton
                               Chicago IL 60621
                               312-535-3190  

Objectives:

  (Adaptable to grade levels 1-2)
  Students should identify salty, sour, bitter, and sweet tastes.  
  Students will investigate the sense of taste.
  Students will investigate that taste buds are not uniformly distributed over 
   the tongue. 

Materials:

 Cotton swabs (sterile), drinking cups (disposable), 4 beakers (400ml), water, 
sugar, baking soda, vinegar, salt, tooth picks, mirror and marking pencils.

Strategy:
 
  Start by giving the students a background of the concept to be developed. 
Taste and smell are connected.  Odors that pass from the mouth to the nose are 
detected and become a part of a food's flavor.  Taste is affected by the texture
and temperature of food.  Taste buds help you taste the things you eat.  A taste 
bud is a small structure that is sensitive to taste.  There are four types of 
taste buds - sour (acid), sweet, salty, and bitter. 
   PART-I.  Go over the procedure to be used in preparing and tasting the 
solutions.  Caution students to follow sterile procedures.  A cotton swab or 
toothpick should be used for tasting a solution and then immediately thrown into 
a trash container.  Each student should use a new swab for each taste.  Be 
certain the beakers or glasses used to hold the solutions are washed and have 
been cleaned.  
   PART-II.  Prepare the solutions using the clean beakers.  Label the beakers 
with the solutions A, B, C, and D. 
   PART-III. Dip a sterile cotton swab into solution A.  Run the swab over your 
tongue.  Record the taste of the solution in your chart.  Rinse your mouth with 
water.  Discard the swab.  Using a new swab each time, repeat the procedure for 
solutions B, C, and D.  Record your results.     
  OPTIONAL ACTIVITY:
  Dip your cotton swab in the solutions.  Touch various areas of the tongue.  
Use a mirror to help locate the most taste - sensitive areas of the tongue.

Performance Assessment:

  After the taste demonstration, unknown food products (two types of cheeses) 
are passed out.  Students will keep their eyes closed and use a nose plug in 
order to distinguish taste.  Then release the nose plug and determine the 
difference in taste, when they are able to smell.  These differences should be 
recorded by each student. 

Conclusion:
  
  The conclusion will be based on the results and students' interpretation.  The
sense organ for taste is the tongue.  In the tongue are groups of nerve endings 
called tasted buds.  When you chew food, tiny bits of it enter the taste buds 
through openings in the tongue.  Taste buds for each of the four tastes are 
located in different areas of the tongue.  Taste buds that respond to sweetness 
are on the tip of the tongue.  Some of the taste buds for saltiness are also 
there.  At the sides of the tongue are located the taste buds for sourness.  
Taste buds for bitterness are at the back of the tongue.   

   This would be a useful multicultural activity, because it relies on 
participation rather than discussion. 

Reference: 

Home, E., Alexander, J. and Edward V. A Sourcebook for Elementary Science. 
     Chicago: Harcourt Brace Jovanovich, Publishers, 1971.