NEETZoologyBiotechnology - Principles and Processes
The DNA polymerase isolated from the bacterium Thermus aquaticus is widely used in Polymerase Chain Reaction (PCR). During the PCR cycle, this enzyme must survive the high temperature of step X without denaturing, and it actively synthesizes the new DNA strand during step Y. Identify step X and step Y.
Options
- AX - Annealing, Y - Extension
- BX - Denaturation, Y - Annealing
- CX - Extension, Y - Denaturation
- DX - Denaturation, Y - Extension
Correct answer
D. X - Denaturation, Y - Extension
Step-by-step solution
In a Polymerase Chain Reaction (PCR), the first step is Denaturation (step X), where the double-stranded DNA is heated to a high temperature (around 94^ C ) to separate the strands. The DNA polymerase isolated from Thermus aquaticus (Taq polymerase) is thermostable and remains active despite this high temperature. The third step is Extension (step Y), where the Taq polymerase actively adds nucleotides to the primers to synthesize the new complementary DNA strand at an optimal temperature of around 72^ C . Thus, ste