DNA Replication Flashcards
Name the requirements for replication
- DNA template
- primers( short strands of nucleotides)
- supply of nucleotides
- ATP
- Enzymes (DNA polymerase & ligase)
Prior to cell division what is DNA replicated by
DNA polymerase
When DNA unwinds what happens
Hydrogen bonds between bases break to form 2 template strands
What end must the primer bond to , to start replication
3’ end
What does DNA polymerase add to the template strands
New complentary nucleotides
Where do DNA polymerase only add new nucleotides
Only in one direction 3’-5’ on the parent strand
What does DNA polymerase bind to
Binds to the primer , which indicates the starting point for replication. This occurs at several locations on DNA strand.
What is the replication like in the leading strand
Replicated continuously
What is replication like in the lagging strand
New nucleotides can only be added to 3’ send so is replicated in fragments with many primers
What joins the fragments together in the lagging strand
Ligase
Flow chart for DNA replication
1) DNA unwinds and hydrogen bonds break
2) primer binds to 3’ end
3) DNA polymerase adds complemtary nucleotides 3’-5’
4) ligase joins fragments in lagging strand together
What does PCR stand for
Polymerase Chain Reaction
What does PCR do
Long answer
Amplifies DNA using complementary primers (short strands of nucleotides) which are complementary to specific target sequences at two ends of the region of DNA to be amplified
What is stage 1 in PCR
DNA is heated to 92°c - 98°c to separate the strands
What happenes during the 2nd part of PCR
Mixture is cooled to 50-65°c to allow primers to bind to target sequences
