DNA Replication Flashcards
Outline the basic steps of DNA replication
Strands separate, primer added, complementary strand elongates, lagging strand ligated
What end of the template strand does synthesis begin
3’
What direction on new strand does synthesis go?
5’ to 3’
What is the role of helicase?
Untwist/separate the parent strands
What is the role of topoisomerase?
Relieve strain ahead of the replication fork
What is the role of single-strand binding protein (SSB)?
Keeping the unwound parent strands apart
What is the role of primase?
Lay down a primer at the 3’ end of parent strand
What is the role of DNA pol III?
Synthesize new strand
What is the leading strand?
The parent strand where DNA pol III moves continuously towards the replication fork
What is the lagging strand?
The parent strand where DNA pol III moves away from replication form. DNA made in segments called Okazaki fragments
What is an Okazaki fragment?
Short stretches of the lagging strand where DNA pol III synthesizes AWAY from fork (3’ to 5’ on parent)
What is the role of DNA pol I?
Removes primer (RNA nucleotide) from 5’ end of new strand and replaces with DNA nucleotide
What direction does DNA synthesis occur?
5’ to 3’ of new strand (which is 3’ to 5’ of parent strand)
What is the semiconservative model of replication?
New DNA contains one old strand and one new parent strand
