KA2 - repliaction of DNA :) Flashcards
1
Q
What does DNA replication involve?
A
DNA polymerase and primers
2
Q
What happens prior to cell division?
A
DNA is replicated by DNA polymerase
3
Q
What does DNA polymerase need in order to start repliaction?
A
primers
4
Q
What is a primer in DNA replication?
A
- A short strand of nucleotide which binds to the 3’ end of the template DNA strand
- It allows DNA polymerase to add free DNA nucleotides
5
Q
Explain the whole process of DNA replication
A
- DNA is unwinded and hydrogen bonds are broken to form 2 template strands.
- DNA polymerase adds free DNA nucleotides
- using complimentary base pairing
- to the 3’ end of the strand that is forming
- DNA polymerase adds free DNA nucleotides
- DNA polymerase can only add DNA nucleotides in one direction
Leading (5’ to 3’) continuous
Lagging (3’ to 5’) fragments - The fragments on lagging are joined by ligase
6
Q
What are the requirements for DNA replication?
A
the nucleus must contain:
- DNA (template)
- Primers
- Supply of 4 nucleotides
- DNA polymerase
- Ligase (enzyme)
- ATP (energy)
7
Q
What is PCR?
A
- PCR amplifies DNA by using complimentary primers for specific target sequences.
- Repeated heating and cooling.
8
Q
What are primers in PCR?
A
- Primers are short strands of nucleotides that are complimentary to specific target sequences and the 2 ends of the region of DNA to be amplified.
9
Q
What is the whole process of PCR?
A
- DNA is heated between 92c to 98c to separate the 2 strands of DNA
- Then it is cooled between 50c to 65c to allow primers to bind to the target sequence
- Then it is heated between 70c and 80c for heat tolerant DNA polymerase to replicate the region of DNA
10
Q
What are the requirements for PCR?
A
- original DNA sample (template)
- Specific DNA primers
- 4 types of nucleotides
- heat tolerant DNA polymerase
- Thermal cycler
- Buffer solution (optimum pH)
11
Q
What are the practical applications of PCR?
A
- help solve crimes
- settle paternity suits
- diagnose genetic disorders
