Tasting Bitter

Question 1

what does PTC stand for

Answer 1

PhenylThioCarbimide

Question 2

what percentage of the population can taste PTC as bitter

Answer 2

70%

Question 3

what gene encodes for a protein receptor that mediates the perception of bitterness

Answer 3

TAS2R38

Question 4

how many variations of TAS2R38 nucleotide positions are there in the human population

Answer 4

3

Question 5

to be a strong taster of bitterness what must the gene pattern be

Answer 5

homozygous dominant (homozygous recessive=non-taster, heterozygous=weak taster)

Question 6

name the 3 stages of PCR

Answer 6

denaturation (94), annealing- primers are added to the 2 strands of DNA (50-60), extension-taq DNA polymerase adds the new strands of DNA (72)

Question 7

name the 5 things involved in creating a PCR

Answer 7

-template to be amplified
-forward and reverse primers
-taq DNA polymerase
-dNTPs
-buffer to maintain pH

Question 8

PCR amplifies what region of the TAS2R38 gene

Answer 8

the 312bp region on the 7th chromsome

Question 9

what is the function of the restriction enzymes

Answer 9

to cut DNA at a specific nucleotide sequence called the restriction site

Question 10

the Fnu4H1 restriction enzyme uses what recognition site

Answer 10

GCNGC, it only digests the TAS2R38 gene at this site

Question 11

does the TAS2R38 gene contain single or double nucleotide polymorphisms

Answer 11

single, an individual may be GCTGC or GTTGC at the position 785

Question 12

what leads to taster/non-taster phnotypes

Answer 12

variations in the gene sequence

Question 13

what are taste buds comprised from

Answer 13

thousands of epithelial cells which create receptor proteins that can bind to the bitter protein creating the response