Bitter Taste Lab

58. Hand your lab partner the pineapple juice and ask them to take a sip.

Based on your procedure and results, how is DNA isolated from plant or animal cells? /4

Race in the South has always been a major topic within the canon of southern literature ever since John Smith’s discussion of Native Americans in “The Generall Historie of Virginia.” The majority of this ongoing conversation on race has revolved around African Americans, white people, and Native Americans. However, in Bitter in the Mouth, Monique Truong challenges these stereotypical ideas of race in the South, namely assumptions on how race and outside appearance impact cultural identity and personal ties to southerness. Her primary strategy of doing this is the structure of the paper, where she keeps Linda’s race a secret for the first part of the novel before exploring it in-depth during the second half. Within this larger structure, she uses the juxtaposition of place to contrast southern aspects of Linda’s identity with northern culture and highlights stereotypical cultural markers of southerness such as dialect and food within Linda’s identity. With these strategies, Monique Truong uses the unique point of view of Linda Hammerick, who is racially Asian but culturally southern, to challenge the reader's assumptions of how race affects cultural identity and to expand understandings of what makes someone southern in today’s cultural landscape.

At first a collection of blood and sperm samples from anonymous donors which are then combined into a mixture. The mixture is subjected for DNA extraction using chloroform, phenol and water. Pure DNA is dissolved in water. It is subjected to an enzyme, restriction that cuts the DNA fragments. The short DNA fragments are treated with alkali to make sticky ends.

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.

The first step in determining whether or not an individual was a taster or non-taster of phenylthiocarbamide (PTC) was to obtain a sample of their DNA. Salt water was flushed in cheeks vigorously for 90 seconds and then the salt water was emptied back onto the 15-ml tube. The tube was centrifuged for 2 minutes to produce a pellet at the bottom of the tube. Then, the liquid was drained off of the top of the contents in the tube to leave only the pellet. Next, 15ml of Chelex was added to the tube containing the pellet.

“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

Part 1 The way people perceive taste is impacted by a number of factors. These include, but are not limited to, age, weight, hormones, sickness and disease, smoking, and diet. Diet is the factor that this paper focuses on. Diet is impacted by the way people taste in that people are used to eating a certain amount of additives and preservatives. Some eat a very low amount, while for others, everything they eat contains additives and preservatives. There is a large range, but this paper will be focusing on two sides: people who eat a moderate to high amount of additives and preservatives in their daily life —this group will be referred to as Group 1—and people who eat very little to none—this group will be referred to as Group 2.

Four microcentrifuge tubes were placed in a rack, labeled and numbered, in order to identify the group and the DNA/restriction enzyme that it held. Each of the tubes initially received 10 microliters of reaction buffer. There were two samples of suspect DNA provided along with two restriction enzymes (EcoRI and HindIII). Tubes labeled 1 and 2 received 15 μL of DNA from suspect one while tubes 3 and 4 received 15 μL of DNA from suspect two. Following that, 15 μL of Enzyme 1 (EcoRI) were added to tubes 1 and 3, and 15 μL of Enzyme 2 (HindIII) were added to tubes 2 and 4. (Table 1). The tubes were then gently tapped on the counter to mix the DNA and enzyme solution followed by incubation at 37°C for 45 minutes. After incubation, 5 μL of 10x gel loading dye were added to each of the four tubes of suspect DNA. The tubes were then placed on ice while the gel was under preparation.

However, DNA fragments of 3 lab subjects didn’t show up on the gel. The allele

1. In the lab activity the rate of the reaction would slow down because it is harder to find unbroken toothpicks since the amount is decreasing because there are less substrates present. 2. By starting off with 400 times more than 50 toothpicks (increased) from the start, than the reaction rate can keep on getting faster and faster because the enzyme would have more to react in the process.

To perform each step listed above we needed certain reagents for each process for DNA Extraction we needed a control non-GMO food sample and a testable food sample. Water and a mortar and pestle to grind the sample. Insta gene Matrix was added to two tubes and a water bath. To perform PCR Reactions we needed DNA template that were going to amplify, DNA polymerase, two DNA primers, four DNA base pair subunits and buffers. For electrophoresis we needed PCR product that we collected, molecular weight ruler, and fast blast for staining.

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Label the 3 test tubes with your initials and number each 1,2, and 3. (This allows for them to be distinguished)