U1 KA2 Flashcards
1
Q
What is needed for DNA replication? (5)
A
- template DNA
- primers
- enzymes
- a supply of nucleotides
- ATP
2
Q
What is Polymerase?
A
- an enzyme that creates DNA molecules by assembling nucleotides.
3
Q
What is Ligase?
A
- an enzyme that joins together fragments of DNA.
4
Q
What are Primers?
A
- short strands of nucleotides that bind to the complimentary DNA template strand, allowing Polymerase to add free nucleotides.
5
Q
What direction does DNA Replication occur?
A
- 5’ to 3’.
6
Q
Stage 1 DNA Replication stages. (2)
A
- the DNA molecule unwinds.
- the weak hydrogen bonds between the base pairs break, allowing strand separation.
7
Q
Stage 2 DNA Replication Leading Strand. (2)
A
- primer binds to the 3’ end of the template DNA.
- using complimentary base pairings, polymerase adds free nucleotides to the 3’ end of the primer.
8
Q
Stage 2 DNA Replication Lagging Strand. (3)
A
- primers pair with the complimentary bases at each fragment.
- polymerase adds free nucleotides to the 3’ end of the primers.
- ligase joins the DNA fragments to form a continuous strand.
9
Q
Stage 3 DNA Replication. (2)
A
- all primers are replaced by DNA.
- both strands wind up to form the double helix structure.
10
Q
Why is the Lagging Strand replicated in fragments?
A
- DNA polymerase can only add nucleotides onto the 3’ end, therefore, the opposite strand has to be replicated in fragments.
11
Q
What is PCR used for?
A
- Polymerase Chain Reaction is used to amplify specific DNA.
12
Q
Name 1 practical application of PCR.
A
- DNA profiling.
13
Q
What is required for PCR? (4)
A
- template DNA
- taq polymerase
- a supply of nucleotides
- Primers
14
Q
Describe the process of PCR. (4)
A
- DNA is heated to 95°C breaking apart the hydrogen bonds, and separating the two strands.
- DNA is cooled to 60°C to allow Primers to bind the target sequences.
- DNA is then heated to 75°C to allow Taq Polymerase to replicate the DNA.
- two identical DNA molecules have been produced.
15
Q
What technique is used to separate macromolecules?
A
- gel electrophoresis.
