Taste Phenylthiocarbamide: A Genetic Analysis

Often, we do not realize just how important our taste and smell senses are to every day life. We go about our day and do the normal human thing. We sleep, eat, shower, get dressed, go to school, work, etc. What if our sense of taste and smell were taken away? How would it change these every day routines? If there were a house fire while we were sleeping and we could not smell the smoke, what would happen? What if we could not taste or smell the food we were eating? What if we could not smell if our bodies were clean when we showered? As a nurse, what if I could not smell a foul odor in regards to urine or

In previous studies, Frank and Byram’s article suggest that taste and smell interactions are dependent on taste and odor. In their experiments, they gave subjects strawberry

Most people believe taste is versatile, but there are only five tastes our tongue can discriminate, which are: sweet, salty, sour, bitter, and umami. Each of these tastes have their own receptors within the taste buds, and each receptor has its own ligand. Most of the tastes are ionotropic receptive, but umami, the taste for meaty and savory, is a metabotropic glutamate receptor (book). That wonderful meaty taste from MSG (monosodium glutamate) is activated in the umami receptors, creating a signal that fools people’s brains. Although umami is an amazing taste to have, it is not the main taste enhanced when a person is a supertaster. A person considered to be a supertaster has greater than normal amount of papillae, which contain the taste

L.H Snyder states that if PTC bitterness taste is inherited, if it would be safe to for it to be referred as a Mendelian

Introduction - Background - PTC stands for Phenylthiocarbamide, a chemical that can either taste very bitter, or nothing at all depending on the genetic makeup of the subject. People who can taste this are supertasters. Supertasters are people who are more sensitive to taste than others, this is linked to the tas2r38 gene. Another link to supertasting is fungiform papillae density. Fungiform papillae are club shaped parts on the tongue that a slightly raised over the rest of the tongue; they have taste buds that can distinguish between the five tastes sweet, sour, bitter, salty, and umami.

Tastes and smells are the perception of chemicals in the air. The close relationship with smell and taste helps people perceive the flavors of food. Anyone with a cold has experienced that moment where they can not perceive the flavors of food because their smell has been “impaired” due to a stuffy nose. Taste itself is focused chemicals that have sweet, salty, sour, bitter, or savory taste. “The sense of taste influences food

“Phenylthiocarbamide (PTC) and its chemically related compound, 6-n-propylthiouracil (PROP), provide extremely bitter taste to some subjects (tasters) but are tasteless or only slightly bitter to others (nontasters)” (Hong, et al.,711-15). There have been many experiments done to examine the relationship between PTC tasting and food preferences. “Although PTC itself has not been found in nature, the ability to taste PTC is correlated strongly with the ability to taste other naturally occurring bitter substances, many of which are toxic. Furthermore, variation in PTC taste sensitivity has been correlated with dietary preferences that may have significant health effects” (Wooding, et al., 637-646). Therefore, differences in PTC tasting can correspond with sensitivity to diseases that are related to diets in the human population. “The ability to taste the bitter compounds PTC and PROP was found to be a protective factor against cigarette smoking. On the other hand, PTC tasters may perceive vegetables such as cauliflower, cabbage, broccoli, and Brussels sprouts as unpleasantly bitter” (Floriano, et al., 931-941). Based on the information above one can conclude that PTC tasters are less susceptible to smoking cigarettes but they are also less likely to consume food that contain beneficial nutrients. A crucial point to understand is that although cruciferous

Receptor proteins recognize bitter-tasting compounds on the surface of taste cells. There are approximately 30 genes for different bitter taste receptors. The gene for the PTC taste receptor, TAS2R38, was identified in 2003. Sequencing identified three nucleotide positions that vary within the human population (Kim et al.); each variable position is termed a single nucleotide polymorphism (SNP). One specific combination of the three SNPs, termed a haplotype, correlates most strongly with tasting ability. In this lab, non-tasters (homozygous recessive, tt) can determine their genotype without having to run the PCR and electrophoresis because non-taster gene is recessive. Thus, the only way for them to express recessive phenotype is to have the tt alleles of

In Experiment 1b, animals given access to Boost® without ethanol consumed on average more than twice as much fluid (ml/kg) per intake session than their ethanol-drinking counterparts in Experiment 1a. This is likely to be due to the high palatability of chocolate Boost ® for adolescent rats, which is diminished by the combination of the bitter/sweet taste properties of

The human body has various sorts of qualities that control the capacity to taste substances experienced on a regular basis. PTC is a compound powder that perceives the intensity of acidity taste for some individuals, however not all individuals can taste it (Harris, H. 1950). The vicinity

point that flavors and smells are not just that, flavors sometimes have tehe ability to

b) High order conditioning can be illustrated in this problem of vomiting and nausea where a patient who drank lemon –lime Kool-Aid before their therapy sessions developed anxiety disorders. They continued to feel anxious even when the drink was offered in their homes rather than at the clinic.

My first experiment I had John taste an apple cider vinegar and mixed salt water solution. John had to take a teaspoon of the solution and place it on his tongue for 30 seconds until it dissolved. John then had to draw out a chart with all five areas of taste , bitter , sweet,sour,umani,and salty rating which

Garcia et al research (Mazure, 2004) proves otherwise, as he shows rats initially made to drink the saccharine-flavoured water, injected with the poison after a delayed interval between the drinking and the drug, developed aversions to the saccharine flavoured water even after 24hours of delay. This illustrates, even when the CS-US is delayed, learning takes place and the ability to do so is adaptive in all species supporting that a general process learning theory is effective. The rat’s biological make-up has an innate tendency to associate illness with the taste of food previously eaten after one trial. Pairing a light with a paw shock, on the other hand, takes several trials to acquire and has low tendency to associate illness with visual or auditory stimuli. Whereas the rats are more likely to associate a painful event like shock with external auditory and visual than with taste stimuli. This revolves around preparedness and we can say that the laws of learning may vary with preparedness of the organism for the association and for those different physiological and cognitive mechanisms (McGowan, & Green, 1971). Louge (1981) also supports taste aversion as a classical conditioning biological constraint learned behaviour on humans as he carried out a questionnaire which resulted in students declaring they were aversive to certain foods. Characteristics, such as smell, sight and texture were also discovered.

The process of tasting is happy for me, I enjoy the feeling that food melt in my mouse and the flavour disperse gradually. But it also exists some problems, I have the keen taste sense and smell over the average,