1. DNA Replication Notes

2. Why must DNA replicate? Cells will divide to make more cells and there must be a full copy of DNA in each cellCells will divide to make more cells and there must be a full copy of DNA in each cell Before a cell can divide into 2 cells, DNA will make a complete copy of itselfBefore a cell can divide into 2 cells, DNA will make a complete copy of itself Each cell must have a full copy of DNA, not just partEach cell must have a full copy of DNA, not just part

3. Why must DNA replicate? 46

4. Definition of Replication Replication is the copying of DNAReplication is the copying of DNA

5. Steps of Replication Step 1:Step 1: DNA must unwind and unzip.DNA must unwind and unzip. The weak Hydrogen bonds that hold the DNA strand together in the middle are broken by an enzyme.The weak Hydrogen bonds that hold the DNA strand together in the middle are broken by an enzyme.

6. Steps of Replication Step 1 (Picture):Step 1 (Picture): A - T A - T T - A T - A C - G Enzyme unzips C - G Enzyme unzips G C DNA at the G C DNA at the A T WEAK A T WEAK G C hydrogen bonds G C hydrogen bonds G C G C

7. Steps of Replication Step #2:Step #2: The DNA strand pulls apart and free DNA nucleotides (that are floating around in the nucleus) begin to pair up with their complementary nucleotide on the parent strand with the help of an enzyme.The DNA strand pulls apart and free DNA nucleotides (that are floating around in the nucleus) begin to pair up with their complementary nucleotide on the parent strand with the help of an enzyme.

8. Steps of Replication Step #2 (Picture):Step #2 (Picture): A - T T Free DNA A - T T Free DNA T – A A nucleotides T – A A nucleotides C – G G floating in C – G G floating in G – C C the nucleus G – C C the nucleus A A - T A A - T G G – C G G – C G G - C G G - C T G G G A A C

9. Steps of Replication Step #3:Step #3: The free nucleotides continue to pair up until the entire double strand of DNA has been copied.The free nucleotides continue to pair up until the entire double strand of DNA has been copied. End result: 2 complete sets of DNA are made; one for each of the 2 new cells being made.End result: 2 complete sets of DNA are made; one for each of the 2 new cells being made.

10. Steps of Replication Step #3: (Picture)Step #3: (Picture) A - T A – T A - T A – T T – A T - A 2 identical T – A T - A 2 identical C – G C - G strands of C – G C - G strands of G – C G – C DNA G – C G – C DNA A - T A - T A - T A - T G - C G – C G - C G – C parent new new parent parent new new parent

11. DNA Replication Animations http://www.stolaf.edu/people/giannini/ flashanimat/molgenetics/dna- rna2.swfhttp://www.stolaf.edu/people/giannini/ flashanimat/molgenetics/dna- rna2.swfhttp://www.stolaf.edu/people/giannini/ flashanimat/molgenetics/dna- rna2.swfhttp://www.stolaf.edu/people/giannini/ flashanimat/molgenetics/dna- rna2.swf http://highered.mcgraw- hill.com/sites/0072437316/student_vi ew0/chapter14/animations.html# (click on how nucleotides are added)http://highered.mcgraw- hill.com/sites/0072437316/student_vi ew0/chapter14/animations.html# (click on how nucleotides are added)http://highered.mcgraw- hill.com/sites/0072437316/student_vi ew0/chapter14/animations.html#http://highered.mcgraw- hill.com/sites/0072437316/student_vi ew0/chapter14/animations.html#

12. DNA Replication Simulation DNA Replication Simulation Make sure Biological Simulations CD is in the drive DNA Replication in real time.