SFH
DNA REPLICATION VIDEO NOTES
http://www.youtube.com/watch?v=GcrndR-zdyM&list=UU7w8FGPEZXF1LQX3B-IvE8A&index=4&feature=plcp
Cells regenerate to replace the ones that are lost or damaged. This occurs in a process called
________________ in which one cell divides to produce an identical copy of itself. If the cell is
to be identical it must also have the same copy of __ __ __. DNA ________________ is the
process where DNA makes an exact copy of itself for a new daughter cell just before mitosis.
DNA replication is semi-_________________ which means that the parent DNA strand splits in
half and a each half adds a new comp______ntary strand. The result is that each of the two
double stranded molecules of DNA is half ______ and half ______. How does this happen?
The first step is for an enzyme called helicase to _________ the double stranded DNA
molecule (separating the two strands by ______________ the hydrogen bonds between A - T
and C - G). Next an enzyme called primase puts an RNA primer on the DNA molecule. DNA
polymerase then adds complimentary nucleotides to the RNA primer, following
_____________’s rule (A-T; C-G). DNA Polymerase continues to move along the DNA molecule
adding complimentary nucleotides as it goes.
Finally an enzyme called DNA ligase comes along and seals up any gaps in the sugar phosphate
backbone of the DNA molecule. DNA Replication results in two identical copies of DNA that is
half old and half new. The new copy of DNA is ready to be placed into a new cell.
** In the above diagram, color the parental strands red and the daughter strands blue.