1 / 11

Hardy-Weinberg Lab

Hardy-Weinberg Lab. Taste Testing. PTC. Phenylthiocarbamide Compound contains sulfur Harmless chemical Found in Brassica family of plants Cabbages, brussel sprouts, kale Gives a slight bitterness. Tasting PTC. Dominant: Tasters Find low concentrations of PTC extremely bitter

simone
Download Presentation

Hardy-Weinberg Lab

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Hardy-Weinberg Lab Taste Testing

  2. PTC • Phenylthiocarbamide • Compound contains sulfur • Harmless chemical • Found in Brassica family of plants • Cabbages, brussel sprouts, kale • Gives a slight bitterness

  3. Tasting PTC • Dominant: Tasters • Find low concentrations of PTC extremely bitter • Homozygous tasters seem to have a very low tolerance • Find it more bitter than heterozygous tasters • Oddity: you can only taste it if it is dissolved in your own saliva • Recessive: Non-tasters • Report little or no taste

  4. How does this reflect on role of alleles? • Alleles are different versions of same gene. • Gene encodes a protein receptor for PTC • Found on chromosome 7 • Tasters have a gene that encode • Proline, Alanine and Valine at positions 49, 262 and 296 • Non-tasters have a gene • A, V and I at these three positions

  5. Sodium benzoate • Poly-unsaturated fat • Used in food to inhibit microbial growth • Works best in an acidic environment

  6. PTC bitter/Sodium benzoate salty Tend to like sauerkraut, buttermilk, turnips and spinach more than average PTC bitter/Sodium benzoate bitter Tend to dislike sauerkraut, buttermilk, turnips, spinach less than average Relation to a person’s fave foods

  7. Most common taste groups • Ranked in order of most common combos PTCSodium Benzoate • 1. Bitter salty • 2. Bitter sweet • 3. Bitter Bitter • 4. Tasteless Salty • 5. Any other combinations

  8. Lab Methods • Part I: PTC Taste/NonTaste • Step 1: Place control paper on tongue/chew a little • Negative control: you shouldn’t taste anything • Something to compare the other papers to… • Step 2: Place PTC(blue paper) on tongue • Record what you taste • If you don’t taste anything, chew it a little and record again • Are you a taster or a non-taster?

  9. Lab Methods…pt 1 • Step 3: Record your PTC data on the board and collect all class data • Step 4: Calculate the allele frequencies and the genotype frequencies of the class

  10. Lab Methods pt 2 • thiourea • How many of you can taste one but not the other?

  11. Lab Methods: Pt 3 • Sodium benzoate

More Related