Why Must DNA Be Denatured During PCR

Question

Why must DNA be denatured during PCR?
A)DNA polymerases work best at higher temperatures.
B)Denaturing DNA separates the strands of DNA and allows primers to bind to complementary sequences.
C)The degraded DNA nucleotides are recycled during the synthesis step of PCR.
D)DNA does not need to be denatured for PCR to work.

Accepted Answer

Denaturing DNA separates the strands of DNA, which allows primers to bind to complementary sequences. This is important for PCR because the primers serve as a starting point for DNA polymerase to extend and amplify the target sequence. If the DNA strands were not denatured, the primers would not be able to bind and initiate PCR. Additionally, DNA polymerases used in PCR generally have an optimal temperature range around 72°C, which is achieved by denaturing the DNA at a higher temperature (usually around 95°C).