PTC: Genes and Bitter TasteMs. Z1/8/10

To Taste Or Not To Taste?

PhenylthiocarbamideAccidentally discovered in 1931 by Arthur

Fox.Tastes extremely bitter to some people but

not others.Chemical structure resembles toxins found

in plants.

The PTC GeneThe ability to taste PTC is determined by a

single gene, which codes for a taste receptor on your tongue.

There are 2 alleles: taster (T) or non-taster (t).

For the PTC gene:How many genotypes are possible?How many phenotypes are possible?

To Taste Or Not To Taste?You will inventory the PTC-tasting trait in

your family and build a pedigree.Are you testing for genotype or phenotype?

Evolutionary Importance of Bitter TasteMany natural bitter substances are toxins.Plants produce many toxins in order to

protect themselves from being eaten.Bitter taste evolved in early humans to

prevent consumption of poisonous plants.

Health ApplicationsPeople who find PTC bitter may be less

likely to smoke, because they find the taste of cigarettes bitter.

The ability to taste PTC may also correlate to food preferences.