Question

In the polymerase chain reaction, DNA is heated to 95 degrees Celsius and nucleotides, enzymes and DNA primers are added to the mixture. What is the advantage of the enzyme used in the polymerase chain reaction being thermostable?

Answer 1

PCR (Polymerase chain reaction) is used to amplify a particular DNA fragment. It has 3 stages 1. Denaturation 2. Anneling 3. Extension

Denaturation takes place at high temperature (~95°C). High temperature is used to denature the DNA double strand so that in the next step primers bind to the single strands DNA followed by extension step, where DNA polymerase help in synthesis of new strand.

Most of the enzymes gets denatured at higher temperature and become inactive or Non-functional, so we use thermostable DNA polymerase which enables running the PCR at high temperature i,e it can also work at higher temprature.

If we use high temprature during PCR it reduces the production of secondary structures during polymerization and prevents non-specific bindings such as primer dimer, also high temprature leads to specific binding of the primer to it's DNA template. So, when we use thermostable enzymes we can run the PCR at high temprature and these problems would be avoided.