Using Polymerase Chain Reaction to Detect Bitter-Tasting

Question 1

receptors

Answer 1

receives chemical signals from outside a cell

example: molecule binds with it and signals its presence to the brain as one of the tastes.

Question 2

gene expression

Answer 2

the process by which the instructions in our DNA are converted into a functional product, such as a protein.

Question 3

phenylthiocarbamide (PTC)

Answer 3

bitter tasting compound detected by some, but not all, humans

Question 4

gene

Answer 4

determined by genetics
humans have 2 copies
Example: TASR2R38

Question 5

TASR2R38 gene

Answer 5

• Determines whether an individual detects a powerful bitter taste, slightly bitter, or no taste at all.
• Two of the most common variations differ at only one nucleotide- single nucleotide polymorphism (SNP.

Question 6

genotype

Answer 6

genetic identity

Question 7

Chelex

Answer 7

membrane, DNA

Question 8

Chelex bead

Answer 8

TAQ poly
nucleotides
pH buffer
salts

Question 9

Cheek cell DNA extraction

Answer 9

1. Saline solution in mouth, rinse cheek and spit.
   Saline is an isotonic solution for the cheek cells.
2. Centrifuge- pellet is the concentrated cheek cell and supernantant is the trash/buffers, etc.
3. Add suspended cheeck celss to Chelex and boil. The boiling lyses the cell.
4. Centrifuge again. DNA will be in supernatant and the pellet is protein.
5. Pipette DNA supernantant into tube with Chelex bead- bead contains TAQ poly and nucleotides & pH buffer

Question 10

Cheek cell DNA extraction

Answer 10

1. Saline solution in mouth, rinse cheek and spit.
   Saline is an isotonic solution for the cheek cells.
2. Centrifuge- pellet is the concentrated cheek cell and supernantant is the trash/buffers, etc.
3. Add suspended cheek cells to Chelex and boil. The boiling lyses the cell.
4. Centrifuge again. DNA will be in supernatant and the pellet is protein.
5. Pipette DNA supernantant into tube clean tube
6. Add PTC primer/dye to PCR bead (taq poly, nucleotides, ph buffers) and dissolve.
7. Pipette cheek cell DNA into the primer/dye.
8. Thermal cycle
   -denaturing (94 C) 30 sec
   -annealing (64C) 45 sec
   -extending (72C) 45 sec

Question 11

Cheek cell DNA extraction

Answer 11

1. Saline solution in mouth, rinse cheek and spit.
   Saline is an isotonic solution for the cheek cells.
2. Centrifuge- pellet is the concentrated cheek cell and supernantant is the trash/buffers, etc.
3. Add suspended cheek cells to Chelex and boil. The boiling lyses the cell.
4. Centrifuge again. DNA will be in supernatant and the pellet is protein.
5. Pipette DNA supernantant into tube clean tube
6. Add PTC primer/dye to PCR bead (taq poly, nucleotides, ph buffers) and dissolve.
7. Pipette cheek cell DNA into the primer/dye.
8. Thermal cycle
   -denaturing (94 C) 30 sec
   -annealing (64C) 45 sec
   -extending (72C) 45 sec

Question 12

restriction enzyme

Answer 12

can cleave DNA at or near a specific sequence of bases.

Question 13

Hae III

Answer 13

SNP at bitter PTC compound

Question 14

electrophoresis gel

Answer 14

method for separation and analysis of macromolecules

Question 15

Hae III

Answer 15

SNP at GGCC only

Question 16

electrophoresis gel

Answer 16

method for separation and analysis of macromolecules

Question 17

tt nontaster

Answer 17

homozygous recessive

Question 18

TT taster

Answer 18

homozygous dominant

Question 19

Tt taster

Answer 19

heterozygous