PTC Lab UPDATED ACTUAL Exam
Questions and CORRECT Answers
Purpose of this lab - CORRECT ANSWER - Analyze our own DNA to see what form of
TAS2R38 (taster gene): heterozygous, homozygous (dominant or recessive)
What did we use to extract DNA from us? - CORRECT ANSWER - Saline solution
Importance of saline solution - CORRECT ANSWER - Salt neutralizes the negative
charge of the sugar phosphate backbone of DNA --> causes DNA to become less hydrophilic
Scraped away cells from mouth
Centrifuge - CORRECT ANSWER - device to separate substances by spinning them at
high speed
What happens when we spun the centrifuge after using the saline solution? - CORRECT
ANSWER - makes the heavier molecules move to the bottom of the test tube; pushed cells
to the bottom which formed a pellet (will be used for DNA extraction)
After centrifuging the 1st time, what did we do - CORRECT ANSWER - added lysis
buffer (red) to resuspend the cell
lysis buffer - CORRECT ANSWER - solution (which had proteinase K) used to break the
cell membrane and release cell contents (DNA)
why did we do a water bath for 55°C? - CORRECT ANSWER - incubate the cell solution
during cell lysis;
- Optimal temperature for the enzyme Proteinase K to actively destroy cellular machinery.
Questions and CORRECT Answers
Purpose of this lab - CORRECT ANSWER - Analyze our own DNA to see what form of
TAS2R38 (taster gene): heterozygous, homozygous (dominant or recessive)
What did we use to extract DNA from us? - CORRECT ANSWER - Saline solution
Importance of saline solution - CORRECT ANSWER - Salt neutralizes the negative
charge of the sugar phosphate backbone of DNA --> causes DNA to become less hydrophilic
Scraped away cells from mouth
Centrifuge - CORRECT ANSWER - device to separate substances by spinning them at
high speed
What happens when we spun the centrifuge after using the saline solution? - CORRECT
ANSWER - makes the heavier molecules move to the bottom of the test tube; pushed cells
to the bottom which formed a pellet (will be used for DNA extraction)
After centrifuging the 1st time, what did we do - CORRECT ANSWER - added lysis
buffer (red) to resuspend the cell
lysis buffer - CORRECT ANSWER - solution (which had proteinase K) used to break the
cell membrane and release cell contents (DNA)
why did we do a water bath for 55°C? - CORRECT ANSWER - incubate the cell solution
during cell lysis;
- Optimal temperature for the enzyme Proteinase K to actively destroy cellular machinery.
