Question

You will need the information in this file to complete the two lab sequence

This is the file that contains the report page for Lab 13-Taste, part 1

There are two things for you to turn in

Enter your taste data on the following page. You should all be able to edit and save the page.

Lab #13 - Taste Data W18

Taste Background

Background

Introduction

Taste is the least understood of all the senses. (PBS, 2000) Taste has been difficult to study because the receptors are not grouped in one restricted place, as they are in the retina of the eye and the organ of Corti in the Cochlea of the ear. Also, the nerves that pick up the taste signal go to various different parts of the brain, unlike those of the eye, ear and nose. In addition because the mouth is a very damp environment, taste molecules quickly diffuse to different places in the mouth so it is difficult to tell exactly what taste receptor is picking up the signal. This complexity lead to the incorrect idea that different kinds of flavors are picked up in only isolated parts of the tongue. The truth is that the receptors for all the different kinds of flavors are all over the tongue, part of the soft palate and a short way down the esophagus.

There are five types of taste receptors, those for salt, sweet, bitter, umami and sour. There is only one type of sour taste bud and they detect acids (hydrogen ions or H+). There is only one type of salt taste bud (detect sodium ions, Na+) and only one type of sweet taste bud (detects sugar). Every normal person has all three of these types of taste buds. In addition there are at least three different kinds of Umami receptors and many different kinds of bitter taste buds and not everyone has the same types. (Westbrook, 2009) There is a huge amount of genetic diversity in the human ability to taste. (Westbrook, 2009)

Genetics

“There is scientific evidence that supports the hypothesis that there is a genetic basis for food preferences. The genes have been found for salt sweet and sour and several have been found for umami and bitter taste receptors. In particular, one bitter receptor detects a compound called PTC. The ability to taste this compound is carried by one allele (dominant - B) for this gene and the other possible allele (b) codes for a non-functional receptor. Someone with the genotype bb cannot taste PTC, with genotype Bb can taste PTC and with genotype BB can taste PTC really well. The PTC-tasting allele is about as common as the non-taster allele. (Westbrook, 2009) Supertasters have a rare allele on a different gene that increases the intensity of many tastes, not just PTC. (Westbrook, 2009)

Supertasters

A supertaster is a person whose sense of taste is significantly more sensitive than average. The cause of this heightened response is thought to be, at least in part, due to an increased number of fungiform papillae (a type of tastebud – See the section below on Anatomy). (Baroshuk, 1994) (Wikipedia)

Each of us is born with a genetically determined number of taste buds. People can be divided into three groups: supertasters (25% of the population), medium tasters (50%) and non-tasters (25%). Supertasters have many more taste buds per square centimeter (thousands per square inch) than medium tasters or non-tasters (a few hundred total). Evidence suggests that supertasters are more sensitive to bitter tastes and fattiness in food, and often show lower acceptance of foods that are high in these taste qualities. Supertasters tend to dislike strong, bitter foods like raw broccoli, grapefruit juice, coffee and dark chocolate. (The Supertaster Test) Supertasters also seem to experience the temperature and texture of foods more keenly than medium tasters and non-tasters. (PBS, 2000)

Some people have speculated that there might be advantages or disadvantages to being a supertaster based on the environment. (PBS, 2000)

Evolution

Taste receptors probably evolved to help us detect good and potentially bad things in our food. Good things (or those that please us) include sugar, salt, and protein and we have specific receptors or pairs of receptors to detect these. Sourness (acidity) can be a sign that otherwise good food has spoiled, and often bitter taste is associated with plant material that is poisonous. (23andme) To protect themselves animals can run away or fight. Plants have the same kind of evolutionary need to protect themselves as we do. A plant can make thorns or poisonous chemicals to deter animals from eating it. The poisonous compounds in plants have many different structures. Our sense of taste can help protect us from these poisons so it isn’t surprising that the family of bitter taste genes encodes at least 25 different receptors. (23andme)

PTC, which we will be testing in this lab, is a very bitter compound, and those who can taste it will usually dislike the flavor. Since bitter compounds are found in vegetables like broccoli, cabbage, turnips, and kale, people who can taste PTC usually don’t like their veggies. (Westbrook, 2009)

Advantages and Disadvantages to being a Supertaster

Advantages: During evolution, supertasters would have had an advantage in environments with lots of poisonous plants with bitter tastes. The supertasters would have perceived the greatest bitterness and thus would have been the most likely to avoid the plants. (PBS, 2000) (F. D. Kitchin, 1959 April 25: 1069-1074)

Disadvantages: PTC tasters are less likely to eat vegetables because many of them have a bitter taste. Some bitter tasting foods contain phytochemicals which are actually healthy to eat (e.g., protect against cancer). Supertasters might like these foods less, eat fewer of them, and suffer from diseases that those foods might have prevented. Supertasters perceive the most intense sensations from salt, acids, and sweeteners as well as from fats in foods. Thus one's ability to taste PTC may turn out to be important to a variety of health problems where diet plays a role. (PBS, 2000) (Richter, 1942) (Westbrook, 2009)

Advantages and Disadvantages to being a non-taster

Advantages: In an environment with bitter plants that are not poisonous, the non-tasters have the advantage because they have a bigger food world.

Disadvantages: People who cannot taste PTC tend to ingest more of similar compounds. One example of a natural compound similar to PTC is a chemical found in turnips and cabbage. (Brussels sprouts are a kind of cabbage.) Although cabbage is not generally toxic, eating a lot of it sometimes causes goiter, a condition in which people have swollen, sometimes enormous, glands in their neck. Goiter is often caused by a lack of iodine in the diet, and today it is found mostly in places where diet is poor and iodized table salt is not widely available. The PTC-like chemical in cabbage makes goiter more likely to occur by blocking the body from absorbing whatever iodine is in the diet. (23andme) (Westbrook, 2009)

Anatomy

Humans receive tastes through sensory organs called taste buds (gustatory calyculi) concentrated on the upper surface of the tongue. (Wikipedia) In most animals, including humans, taste buds are most prevalent on small pegs of epithelium on the tongue called papillae. The taste buds themselves are too small to see without a microscope, but papillae are readily observed by close inspection of the tongue's surface. (The Supertaster Test)

Each fungiform papillae (the mushroom-shaped structures on the tip of your tongue) contains about a half dozen taste buds. Other bumps on the tongue are different kinds of papillae that do not contain taste buds. (PBS, 2000)

Tongue

(The Supertaster Test)

Semidiagrammatic view of a portion of the mucous membrane of the tongue. Two fungiform papillæ are shown. On some of the filiform papillæ the epithelial prolongations stand erect, in one they are spread out, and in three they are folded in.

(Gray, 2a. The Mouth, 1918)

Taste buds are composed of groups of between 50 and 150 columnar taste receptor cells bundled together like a cluster of bananas. The taste receptor cells within a bud are arranged such that their tips form a small taste pore, and through this pore extend microvilli from the taste cells. The microvilli of the taste cells bear taste receptors. (Bowen, 2006)

(Sensory Organs, 2009)

(Bowen, 2006)

(Wikipedia)

Part 1 – Count the number of Papillae you have in a given area of the top of your tongue.

1. Chew a small piece of the blue or green colored candy included in your lab kit or rub the blue lollipop on the your tongue to color it blue. The tiny bumps (the fungiform papillae) on your tongue that house your taste buds don't take up food coloring very well. These are the pink, or light colored spots you see. The more papillae you have, the more taste buds you have and the more sensitive to taste you are.

2. Place one of the reinforcing rings for a three ring binder near the front of your tongue. On average, non-tasters have fewer than 15 papillae in that area, while supertasters have over 25. (23andme) (Test Your Tastebuds)

3. Count the pink/light colored dots within the reinforcement ring. This may be easier with a magnifying glass. You can use the magnifier from lab #1 – Observation. Enter this information into Data Table 1 at the end of the lab.

(Test Your Tastebuds)

(Bowen, 2006)

(PBS, 2000)

Figure 1 Taste buds of Tasters and Non-Tasters.

Part 2 - What molecules do you taste?

As you do this part of the lab, keep in mind the number of papillae you recorded. If you have more than 25 papillae in the test circle be prepared to be a super taster and test a tiny bit of the test paper at first. The candy included in the lab kit is very sour, which should help cover the bitter taste of PTC if it is overwhelming.

Bibliography

   •   23andme. (n.d.). Bitter Taste Perception. Retrieved August 20, 2011, from https://www.23andme.com/health/Bitter-Taste-Perception/howitworks/

   •   Baroshuk, L. V. (1994, 56(6)). PTC/PROP tasting: anatomy, psychophysics, and sex effects. Physiol Behav , pp. 1165-71.

   •   Bowen, R. (2006, December 10). Physiology of Taste. Retrieved October 31, 2011, from http://www.vivo.colostate.edu/hbooks/pathphys/digestion/pregastric/taste.html

   •   Caruso, D. W. (n.d.). What Do You Tast? Retrieved 2011

   •   Chudler. (n.d.). Bitter. Retrieved from http://faculty.washington.edu/chudler/bitter.html

   •   F. D. Kitchin, W. H.-E. (1959 April 25: 1069-1074, April 25 :1(5129):). P.T.C. Taste Response and Thyroid Disease. pp. 1069-1074.

   •   Fox, A. L. (1932). The Relationship between Chemical Constitution and Taste. In A. L. Fox, Genetics (pp. 115-116). Wilmington, Delaware: Jackson Laboratory, E.I. Du Pont de Nemours & Co.

   •   Gray, H. (1918). 2a. The Mouth. In H. Gray, Anatomy of the Human Body (p. figure 1018 paragraph 84). Bartleby.com.

   •   Gray, H. (1918). 2a. The Mouth. In H. Gray, Anatomy of the Human Body (p. fig 1014 paragraph 80). Bartleby.com.

   •   Lindemann, B. (2000). A taste for Umami taste. Nature Neuroscience 3 (2) , pp. 99-100.

   •   NIH. (n.d.). Retrieved from http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=OMIM&dopt=Detailed&tmpl=dispomimTemplate&list_uids=171200

   •   PBS. (n.d.). Peppers. Retrieved August 2011, from Life's Little Questions: Why Are Peppers Hot? : http://www.pbs.org/safarchive/3_ask/archive/qna/3294_peppers.html

   •   PBS. (2000). Science Frontiers. Retrieved August 13, 2011, from http://www.pbs.org/safarchive/4_class/45_pguides/pguide_904/4494_peppers.html#act2

   •   Pennsylvania, U. o. (1994). Retrieved August 12, 2011, from oncolink.upenn.edu/cancer_news/1994/hot_candy.html.

   •   Relative Chili Heat. (n.d.). Retrieved August 12, 2011, from www.wiw.org/~corey/chile/scoville.html

   •   Richter, C. a. (1942). Arch. Path. , pp. 33, 46.

   •   Sensory Organs. (2009, March). Retrieved November 16, 2011, from Aurthurs Clipart: http://www.arthursclipart.org/medical/senseorgans/taste%20buds%202.gif

   •   Test Your Tastebuds. (n.d.). Retrieved August 20, 2011, from http://www.bbc.co.uk/science/humanbody/body/articles/senses/tongue_experiment.shtml

   •   The Supertaster Test. (n.d.). Retrieved August 23, 2011, from http://supertastertest.com

   •   Westbrook, D. a. (2009, January 9). What Do You Taste? Retrieved November 18, 2011, from SPICE: www.spice.centers.ufl.edu/mendelian genetics/deena lesson 1.doc

   •   Wikipedia. (n.d.). Retrieved November 6, 2011, from http://en.sikipedia.org/wiki/taste

13 – Taste Lab, Part One – Collecting the data

There are three sections to this part of the taste lab. The first is to count the number of taste papillae inside a small circle. The second is to determine if you are a taster non-taster or supertaster of PTC. The third is to record your data in the editable file in the taste lab assignment page.

The hypothesis we are testing in the two labs, “13-Taste Lab, Part One” and “13-Taste Lab, Part Two” is: “The more papillae you have (which means more taste buds you have) the more sensitive to taste you are.” In particular we are testing the statements in “23andme” and “Test your Tastebuds” (see the reference list in the background file) that in the front part of the tongue, on average, non-tasters have fewer than 15 papillae while supertasters have over 25.

Section 1 – Count the number of Papillae you have in a given area of the top of your tongue.

(Test Your Tastebuds)

(Bowen, 2006) (PBS, 2000) (PBS, 2000)

   Figure 1 Taste buds of Tasters and Non-Tasters

Procedure

   •   Rub the blue lollipop (or dum-dum) that is included in your lab kit on your tongue to color it blue. The tiny bumps (the fungiform papillae) on your tongue that house your taste buds don't take up food coloring very well. These are the pink, or light colored spots you see.

   •   Place one of the reinforcing rings for a three ring binder near the front of your tongue.

   •   Count the pink/light colored dots within the reinforcement ring. This may be easier with a magnifying glass. You can use the magnifier from lab #1 – Observation. Enter this information into Data Table 1 at the end of the lab.

Section 2 - What kind of taster are you?

As you do this part of the lab, keep in mind the number of papillae you recorded. If you have more than 25 papillae in the test circle be prepared to be a super taster and test a tiny bit of the test paper at first. There is sour candy included in the lab kit which should help cover the bitter taste of PTC if it is overwhelming.

Procedure

   •   Take half of one control taste test strip. Place half the taste strip on your tongue. Record in Table 1 what the test strip tastes like to you. You probably won’t taste anything but if you do, it should taste like paper.

   •   Take half of one PTC taste test strip. Place the half taste strip on your tongue. Check the box in Table 1 that describes how intense the flavor was to you (super taster, taster or non-taster). If you tasted nothing, or if it tasted the same as the control test, you are a non-taster. Otherwise, you are a taster. You are a super taster if you can barely stand the flavor. Your lab kit should contain some kind of sour candy which will help get rid of the taste.

Section 3 – Record your data

Make sure your own data is recorded here in table 1 and on the editable “Canvas page” for Lab #13 – Taste Data.

Suggestion:

When you are finished you may have some of the taste strips left. You can use them to test other members of your family and/or friends.

13 – Taste, Part 1   Lab Report Page   Name   

Specifics for the lab

There are three types of data we will collect in this lab; number of taste buds, taste of the control paper, taste of the PTC paper.

   1) Count and record in table 1 the number of taste buds you have in a given area on your tongue.

   2) Record your taste sensation for the control paper in table 1.

   3) Record in Table 1 whether you are a non-taster, taster or supertaster of PTC.

   4) Enter your taste bud count and what kind of taster you are for PTC in the editable “Canvas page” for Lab #13 – Taste Data.

The class data will be used in 13-Taste, Part 2 - Data Analysis.

Data Table 1

Papillae count Control paper taste PTC (check one box)

   Non-taster taster Super taster

13 – Taste Lab, Part Two, Data Analysis

In 13 – Taste Lab, Part 1 We collected data from everyone in class for number of papillae and type of taster of PTC. This purpose of this part of the lab is to analyze that data.

The hypothesis we are testing in the two labs, “13-Taste Lab, Part One” and “13-Taste Lab, Part Two” is: “The more papillae you have (which means more taste buds you have) the more sensitive to taste you are.” In particular we are testing the statements in “23andme” and “Test your Tastebuds” (see the reference list in the background file) that in the front part of the tongue, on average, non-tasters have fewer than 15 papillae while supertasters have over 25.

There are three sections to this part of the taste lab. The first is to record and organize the class data. The second is to graph the data in a way that will help you see if there is a correlation between number of taste papillae and type of taster. The thirds is to write a conclusion to this lab. A conclusion is an effort to describe what your analyzed data shows and describe whether or not the hypothesis is supported by our data. You also explain what type of experiments can be done to confirm your conclusion.

One example of how to record and analyze the data

Table 1 is the data from the last quarter class. I have left off the names of everyone and you may do the same. To make it easier for me I have color coded each line for how many taste buds that person has. We will be using three categories, 0-15, 16-24 and more than 25. The colors I used are in table 2. You don’t need to use these colors or this way of analyzing the data.

In Table 1 each type of taster is assigned a value. Non-tasters are labeled “0”, Tasters are labeled “1” and super tasters are labeled “2”.

It is unlikely that our data will give a perfect correlation between papillae count and type of taster so I have made another table, Table 3, which has the columns labeled by number of papillae and the rows are for the type of taster that person is. Columns A, B and C don’t really go together. At the bottom of the table the type of taster is averaged for each type of papillae count.

To read this table, for example, for A the type of taster is 0.6. Less than a taster but more than a non-taster.

Figure 1 is an example of one way you can show a graphical relationship between papillae count and type of taster. This particular set of Data shows a good correlation between papillae count and type of taster.

Report Page   Name  

Data Analysis

   1) Collect the data from everyone in the class. The data should be taken directly from the data file on the assignment page in Canvas. You may copy and paste it here or type out your own version. The form should look like Table 1 above (like this).

Data Table

Papillae count	Non-Taster	Taster	Super-Taster

.

.

.

2)   Reorganize your data into something that will help you analyze the data (for example, like Table 3).

3)   Present some kind of graphical representation of the data.

4)   Restate the hypothesis and write a conclusion to this experiment.

5)    Answer the questions at the end of the lab

Questions

   1. What (if any) correlation do you see between the number of papillae you have and the type of taster you are? (Give a short version of your conclusion).

   2. What can you say about the number of taste buds someone has relative to the number of papillae?

   3. Describe a possible evolutionary advantage to being a

A) supertaster -- for animals and humans.

B) non- taster -- for animals and humans.

4. What factors other than number of taste buds might explain a person's food preferences?

Enter your taste bud count and check the box corresponding to whether you are a non-taster, taster or Super taster.

Answer 1

2)   Reorganize your data into something that will help you analyze the data (for example, like Table 3).

3)   Present some kind of graphical representation of the data.

4) In a population majority will be tasters, non tasters and supertasters will be almost equal in number. From answer 2 and 3, we can see that out of 13 students 8 were tasters2 were non tasters and 3 were super tasters which shows that major part of population comprise of tasters and super tasters and non tasters are almost equal in number.

Questions

   1. What (if any) correlation do you see between the number of papillae you have and the type of taster you are? (Give a short version of your conclusion).

No, there was no correlation seen between the number of papillae and the type of taster.

   2. What can you say about the number of taste buds someone has relative to the number of papillae?

More the number of papillae, more the number of taste buds

   3. Describe a possible evolutionary advantage to being a

A) supertaster -- for animals and humans.

Supertasters do not like the bitter taste and tend to avoid poisonous plants with bitter taste.

B) non- taster -- for animals and humans. They tend to eat more healthier food and different variety of foods

4. What factors other than number of taste buds might explain a person's food preferences?

Genetic factor that determines the type of taste receptors on the taste buds also might explain a person’s food preference

Enter your taste bud count and check the box corresponding to whether you are a non-taster, taster or Super taster.

taste bud count= 22, Taster