PCR

Question 1

What is PCR

Answer 1

PCR is a method of copying DNA.

Question 2

What is PCR used for

Answer 2

PCR is used for :
Forensic analysis
Genome comparison of different organisms
Gene amplification of paternity testing

Question 3

Process of PCR (simple)

Answer 3

Simple PCR process is
1) denaturation heat separates DNA strands
2)annealing: cool to allow primers to form H bonds with ends of target sequence
3)DNA polymerase adds nucleotides to 3’ end of each primer
Repeated 20-40times

Question 4

What are DNA primers

Answer 4

DNA primers are short single strands of DNA - required as DNA polymerase can only bind to double stranded DNA

Question 5

What is thermocycler

Answer 5

Thermocycler is machine that automatically alters temperature

Question 6

What is process of PCR

Answer 6

Process of PCR is:
1) Double stranded DNA sample
2)heated to 95degrees to denature DNA down middle
3)reduce temperature to 55degrees allow primers to anneal. Primers will create section of double stranded DNA along each of single strands of sample. So DNA polymerase can bind (can only bind to double stranded)
4) raise temp to 72degrees (optimum temp for DNA polymerase) DNA polymerase binds and extends primers using free nucleotides.
Repeated 20-40times

Question 7

What are characteristics of DNA that makes PCR possible

Answer 7

Characteristics of DNA that makes PCR possible are:
DNA is made of anti parallel strands.
DNA only grows from 3’ end (5’ and 3’ refer to carbons in deoxyribose sugar)

Question 8

What techniques can be used to analyse amplified DNA

Answer 8

Gel electrophoresis and DNA profiling are techniques which can be used to analyse amplified DNA.