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If the sequence of DNA in Question 12 were amplified using 25 PCR cycles, then the amount of this DNA would be predicted to increase by -fold.
18. Biotechnology
The Steps of PCR
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Why is a DNA polymerase from a thermophilic bacterium used in PCR?
A
The enzyme makes DNA that is extremely similar to human DNA.
B
It is cheaper to obtain from live microorganisms than producing the enzyme in a lab.
C
This thermophile's DNA polymerase does not require primers to begin DNA synthesis.
D
This thermophile's DNA polymerase can withstand high temperatures that denature most proteins.
Verified step by step guidance1
Understand the role of DNA polymerase in PCR: DNA polymerase is an enzyme that synthesizes new strands of DNA complementary to the target sequence during the Polymerase Chain Reaction (PCR).
Recognize the conditions of PCR: PCR involves repeated cycles of heating and cooling. The high temperatures are necessary to denature the double-stranded DNA, allowing the primers to anneal to the target sequence.
Identify the challenge with typical DNA polymerases: Most DNA polymerases from non-thermophilic organisms denature at the high temperatures used in PCR, losing their functional shape and activity.
Learn about thermophilic bacteria: Thermophilic bacteria, such as Thermus aquaticus, thrive in high-temperature environments. Their enzymes, including DNA polymerase, are naturally adapted to function at elevated temperatures.
Conclude why thermophilic DNA polymerase is used: The DNA polymerase from thermophilic bacteria can withstand the high temperatures of PCR without denaturing, making it ideal for the process as it remains active throughout the thermal cycles.
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The Steps of PCR practice set
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