Question

Polymerase chain reaction is most useful in which of the following processes?
A) DNA synthesis
B) DNA amplification
C) Protein synthesis
D) Amino acid synthesis

Answer 1

Hint: PCR or Polymerase Chain Reaction is a technique used in molecular biology to create millions of copies of a small segment of DNA. This technique was developed by Kary Mullis. This tool is commonly used in molecular biology and biotechnology labs also.

Complete answer:
The PCR technique is based on the enzymatic replication of DNA. In this process, a short segment of DNA is amplified using primer mediated enzymes. The enzyme used here is DNA Polymerase which synthesises new strands of DNA complementary to the template DNA. The DNA polymerase can add a nucleotide to the pre-existing hydroxyl group only. Primer is required in this process.

Components of PCR include;
I) DNA Template:
II) DNA Polymerase: Taq Polymerase is the enzyme used. It is thermostable and does not denature at very high temperatures.
III) Oligonucleotide Primers: Deoxyribonucleotide triphosphate: These provide energy for polymerization and are the building blocks for the synthesis of DNA.
IV) Buffer System: It includes Magnesium and Potassium which provide optimum conditions for DNA denaturation and renaturation. It is important for fidelity, polymerase activity, and stability.

The polymerase chain reaction is used to amplify or to increase the number of a single copy of DNA with high accuracy and speed. So, the polymerase chain reaction is most useful in DNA Amplification.

DNA synthesis: DNA synthesis is the natural or artificial creation of deoxyribonucleic acid (DNA) molecule.This is done using DNA polymerase enzymes.
Protein synthesis: Protein synthesis is the process in which cells make proteins. It occurs in two stages: transcription and translation. It is done using RNA polymerase enzymes.
Amino acid synthesis: Amino acid synthesis is the set of biochemical processes (metabolic pathways) by which the amino acids are produced.It is done using precursor molecules with simple steps.

Therefore the correct answer is option ‘B’.

Note: Some of the applications of PCR are:
- Testing of genetic disease mutations and Monitoring the gene in gene therapy.
- In forensic science it is used as a tool in genetic fingerprinting.
- It is also used for paternity tests