Download DNA REPLICATION HANDOUT

DNA REPLICATION HANDOUT
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1) Template strands: Original DNA strands that were ripped apart.
2) Replication Fork: Y-shaped region where new strands of DNA are elongated
3) Okazaki Fragments: Only found on the lagging strand. Since DNA is
connected by base pairs, as the original strand “unzips” one of the templates
is running in the 5’ to 3’ direction, while the other is 3’ to 5’. As you know
DNA can only replicate from 5’ to 3’. This presents a problem for the strand
that is replicating off the 3’ to 5’ Template. You cannot have continuous
replication off this strand and end up with a bunch of fragments.
4) Lagging Strand: To elongate the new strand of DNA polymerase must work
along the template away from the replication fork. DNA synthesized in this
direction is the lagging strand.
5) Leading Strand: The new strand of DNA that works towards the replication
fork
6) DNA Ligase: Enzyme that joins Okazaki fragments into a single strand
7) DNA Polymerase: Enzyme that is responsible for elongating DNA at the
replication fork.
8) DNA Helicase: Enzyme which unwinds the parental double helix.
Original picture taken from:
http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/D/DN
AReplication.html
Definitions taken from:
Biology 5th ed. By Campbell Reece and Mitchell