6.3 Manipulating Genomes

Question 1

What does PCR stand for?

Answer 1

Polymerase Chain Reaction

Question 2

What is PCR?

Answer 2

A technology used to amplify a short length of DNA and copy it many times

Question 3

What type of DNA polymerase is used in PCR?

Answer 3

Taq DNA Polymerase

Question 4

What is the advantage of taq DNA polymerase

Answer 4

It is stable at high temperatures which is necesary as normal DNA polymerase would denature at the high temperatures involved in PCR

Question 5

Where is Taq polymerase obtained from?

Answer 5

Thermophilic bacteria (Thermophilus aquaticus) that live in very hot conditions such as geothermal vents

Question 6

What is DNA mixed with in the first stage of PCR

Answer 6

• Taq DNA polymerase
• DNA Primers
• free floating DNA nucleotides
• Magnesium Ions

Question 7

Describe the stages of PCR

Answer 7

-DNA is obtained and mixed with DNA primers,
taq polymerase, free floating DNA nucleotides and Magnesium ions.
-The mixture is heated to 94-96 degrees and the hydrogen bonds between the complementary pairs break and the strands separate
-primers anneal (attach) to the DNA strands as they have complementary pairs. The optimal temperature for this is 68 degrees
-The temperature is raised to 72 degrees and taq DNA polymerase attaches the primers to the DNA strand and catalyses the addition of the nucleotides (forming phosphodiester and hydrogen bonds)
-The cycle repeats, generating more DNA