Phenylthiocarbamide Analysis

792 Words 4 Pages
Analysis of phenotype and genotype using Phenylthiocarbamide (PTC) variation taste sensitivity

Introduction
Taste occurs when chemical signals stimulate taste receptor cells in the oral cavity to detect tastes such as sweet, sour, salty, bitter and umami. PTC taste sensitivity is very common substance used to study taste perception. Many studies have provided insights into tastes perception using sodium benzoate and thiourea. PTC sensitivity has often been used for practical demonstrations in educational settings to demonstrate variation in taste perception. Phenylthiocarbamide (PTC) is an organic compound known to exhibit a distinct taste of bitterness to some people and tasteless to others, therefore understanding taste sensitivity for
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Many of these receptors can be found on many loci of chromosomes and manifested in many organs of the body. Scientist have also discovered that TAS2R genes also elicit defensive mechanisms such as vomiting, excretion and differential in taste bitterness possibly help us to avoid consuming toxic substances. The TAS2R38 gene is the most studied gene loci for bitter taste variation in the TAS2R family. Other studies have provided insights of PTC tasting of humans and chimpanzees to understand evolutionary relationships.
There are many ways to determine the specific genotype and phenotype of an individual’s ability to taste PTC. Previous studies have demonstrated that polymorphisms in human sensory receptor genes can modify perception by expressing unique receptor types. In the years following, Arthur Fox’s discoveries, many twin and population studies have demonstrated that PTC tasting is an inheritable trait following Mendelian pattern of
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So, a person’s ability to taste PTC depends on the type of alleles receive from taster parents. Based on this fact, a person can receive three possible combinations of the two alleles from a parent. A person can get two dominant alleles (TT) tasters, which would be considered homozygous dominant; or two recessive alleles, non-tasters (tt) making that person homozygous recessive; a dominant allele from one parent and a recessive allele form the other parent (Tt) will make that person heterozygous, also a taster of PTC. The genetic makeup of a person at the molecular level and understanding of alleles involved is important for genotype analysis. The purpose of the experiment is to investigate genotype or phenotype for PTC tasting by tasting a PTC test strip in conjunction with other chemicals like thiourea and sodium

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