1.2 Replication of DNA Flashcards
When is DNA replicated?
DNA is replicated prior to cell division
What is the name given to the short sequence of nucleotides required to start the new strand in replication?
Primers are required to start DNA replication
What is a primer?
A primer is a short strand of nucleotides which binds to the 3’ end of the template DNA strand allowing polymerase to add DNA nucleotides.
What happens during the first stage of replication?
During the first stage of replication DNA is unwound and hydrogen bonds between bases are broken to form two template strands.
What is the rule for DNA polymerase in replication?
DNA polymerase can only add DNA nucleotides to the 3’ end of the forming DNA strand
How is the leading strand replicated?
The leading strand is replicated continuously
How is the lagging strand replicated?
The lagging strand is replicated in fragments
What are primers used for in PCR?
In PCR, primers are short strands of nucleotides which are complementary to specific target sequences at the two ends of the region of DNA to be amplified
Why is DNA heated to between 92-98 degrees celsius?
to separate the strands and break the hydrogen bonds
Why is DNA cooled to between 50 and 65 degrees celsius?
To allow primers to bind to target sequences of DNA
Why is DNA then heated between 70 and 80 degrees celsius?
To allow heat tolerant DNA polymerase to replicate the region of DNA?
What are the practical applications of PCR?
Practical applications of PCR include solving crimes, settling paternity suits and diagnosing genetic disorders
