U1 KA2 - DNA Replication Flashcards
What enzyme is responsible for DNA replication?
DNA Polymerase
DNA Polymerase is essential for synthesizing new DNA strands during replication.
What is a Primer in DNA replication?
A short strand of nucleotides that binds to the 3’ end of the template DNA strand
Primers are crucial for initiating the DNA synthesis process.
What happens to DNA before it is replicated?
DNA is unwound and hydrogen bonds between the bases are broken
This process creates two separate template strands for replication.
In which direction can DNA Polymerase add DNA nucleotides?
Only in one direction (3’ to 5’)
This directional limitation results in different replication processes for leading and lagging strands.
How is the Leading Strand replicated?
Continuously
The Leading Strand is synthesized in a continuous manner due to the directionality of DNA Polymerase.
How is the Lagging Strand replicated?
In fragments
The Lagging Strand is synthesized in short segments known as Okazaki fragments.
What enzyme joins the fragments of DNA on the Lagging Strand?
LIGASE
LIGASE is responsible for sealing the gaps between the Okazaki fragments.
What is the purpose of the Polymerase Chain Reaction (PCR)?
To amplify DNA
PCR allows for the exponential increase of specific DNA sequences.
What are the requirements for PCR?
- A DNA Template
- A supply of the 4 types of DNA nucleotides (A, T, C, G)
- Primers
- Heat-tolerant DNA Polymerase
- A pH Buffer
These components are necessary for successful amplification of DNA.
What are the temperature conditions during the first step of PCR?
Heated to between 92 and 98°C
This high temperature is necessary to separate the DNA strands.
What happens during the cooling phase of PCR?
Primers bind to target sequences
Cooling allows the primers to anneal to their complementary sequences on the template DNA.
What is the role of heat-tolerant DNA Polymerase in PCR?
To replicate the region of DNA at elevated temperatures
Heat-tolerant DNA Polymerase is stable during the high-temperature phases of PCR.
After how many cycles of PCR are 128 copies of the original DNA target sequence produced?
After 7 cycles
Each cycle of PCR doubles the amount of DNA present.
Fill in the blank: PCR can amplify DNA for use in solving _______.
CRIMES
PCR is widely used in forensic science to analyze DNA evidence.
Fill in the blank: PCR can also be used to settle _______ suits.
PATERNITY
PCR can provide genetic evidence in legal cases regarding parentage.
True or False: PCR can be used to diagnose genetic disorders.
True
PCR is a powerful tool in medical diagnostics for identifying genetic conditions.
