PCR

Question 1

What does PCR stand for?

Answer 1

Plymerase Chain Reaction

Question 2

What happens to a double stranded DNA molecule when it “denatures”?

Answer 2

When the DNA molecule denatures it has been heated to separate the strands.

Question 3

How does this process occur?

Answer 3

This process occurs by heating up a tube of DNA dissolved in water.

Question 4

What conditions must exist for the DNA to “renature” after the molecule has denatured?

Answer 4

Bring the temperature back down.

Question 5

What are “primers” and what is their role in the PCR process?

Answer 5

Primers are short pieces of DNA that define target sequence.

Question 6

What kind of biochemical is DNA polymerase?

Answer 6

It’s a protein-enzyme.

Question 7

Why is DNA polymerase essential for PCR to be successful?

Answer 7

The DNA polymerase copies a cell’s DNA before it divides in two.

Question 8

PCR requires the use of a special DNA polymerase. What is the name of this special
molecule.

Answer 8

It requires the use of a bacteria called Taq Polymerase.

Question 9

Why is it necessary to use this particular enzyme?

Answer 9

It’s necessary to use this particular enzyme because it can survive near boiling, hi-heat temperatures.

Question 10

In your own words, identify and explain the 3 steps that are necessary to complete the PCR
process. (Be sure to include the temperatures that are required for each step.)

Answer 10

1. DNA strands come apart at the base pairs- 95 degrees
2. Primers attach to the end of the target sequence. 50-60 degrees
3. Taq polymerase attaches to primers and adds bases to (extends) the open DNA strands. 72 degrees

Question 11

Describe 4 situations in which PCR could be used by scientists or medical doctors. (Example: If you discovered a genetic disease ran in your family, how could the PCR
process be useful?)

Answer 11

1. Used to find out if someone has genetic disease mutations
2. Crime scenes
3. Organ transplantation
4. Replicate a gene or make a protein from a replicated gene