Labs Flashcards
PTC 1-4
What was the aim if the labs 1-4?
To identify the gene responsible for tasting bitterness
What is the 6 main stages of the labs?
- Produce a tris ETA buffer // 2. PCR - amplify DNA / / 3. DNA clean up - purifying DNA samples //4. Quantify DNA amount with a nano drop // 5. restriction digestion - adding Fn4H2 enzyme // 6. Agrisé gel electrophoresis - comparing dna bands with a 100bp NEB DNA ladder
What is the genotype for a taster ? And it’s DNA length?
TT homozygous dominant // 216bp and 106 bp
What is the genotype for a weak -taster ? And it’s length in bp
Tt // 300-200bp of two to three bands
What is the genotype for a non taster ? And it’s length
Homozygous recessive // 312 bp
What is the role of the Fn4H2 enzyme
It’s a restriction endonuclease which cuts the DNA when a specific sequence of GCNGC is present ( presnt in tasters ) cutting the DNA strand into two strands of 216bp and 106 bp
What is the use of a negative control ?
To ensure there has been no cross contamination , no band should be present
Describe the 3 stages of PCR
- Denature - DNA helix is heated and template strands seperate // 2. Anneal - primers are added and complimentary sequence is produced //3. Extension = taq DNA polymerase is added and complimentary strands join via hydrogen bonds
What is eluting ?
Removing something from a sample
What piece of technology can be used to measure the amount of DNA ?
Nano drop spectrophotometer
What piece of technology can be used to measure the amount of DNA ?
Nano drop spectrophotometer
How do we detected bitter chemicals in food?
TAS2R38 gene encodes for a PTC receptor protein which binds to PTC , sending signals to the brain for bitter perception
How are SNPs involved in bitter taste perception?
A SNP at the coding region 785,is either PAV / AVI halophytes, with PAV being associated with strong tasters and AVI being associated with weak tasters
