1. On the top ¼ of pg 68: What stage of the cell cycle does DNA replication occur? Why is it important that the DNA is replicated? Please complete the two DNA sequences below : T A C G T A T G A A A C T G G T T T A G A A T T

2. What stage of the cell cycle does DNA replication occur? • S stage or Synthesis • Why is it important that the DNA is replicated? • Each cell must have a full set of DNA T A C G T A T G A A A C A T G C A T A C T T T G T G G T T T A G A A T T A C C A A A T C T T A A

3. 8.3 DNA Replication 2.1 Atoms, Ions, and Molecules • Set up Cornell Notes on pg. 69 • Topic: 8.3 DNA Replication • Essential Question: • Explain how DNA serves as its own template during replication. • How do cells help ensure that DNA replication is accurate? • Don’t forget to add it to your T.O.Contents! • Explain how DNA serves as its own template during replication. • How do cells help ensure that DNA replication is accurate? Key Concept: DNA replication copies the genetic information of a cell.

4. KEY CONCEPT DNA replication copies the genetic information of a cell.

5. What does the word replication mean? • A copy or reproduction.

6. new strand original strand Two molecules of DNA DNA Replication copies the genetic information. complementary

7. The rules of base pairing directreplication. A=T C=G • DNA is replicated during theS (synthesis) stage of thecell cycle. • Each body cell gets acomplete set ofidentical DNA.

8. nucleotide The DNA molecule unzips in both directions. • Enzymes and other proteins do the actual work of replication. 1. Enzymes unzip the double helix. • Free-floating nucleotides form hydrogen bonds with the template strand.

9. nucleotide unzips nucleotides

10. nucleotide new strand DNA polymerase • 2. DNA polymerase (poly-mer-ace) enzymes bond the nucleotides together to form the double helix. complementary

11. nucleotide new strand DNA polymerase complementary

12. new strand original strand Two molecules of DNA 3. Two new molecules of DNA are formed, each with an original strand and a “complementary” newly formed strand. complementary Why do we call the new strand a complementary strand and not an identical strand?

13. new strand original strand Two molecules of DNA Complementary New strand Original strand

14. new strand original strand Two molecules of DNA DNA is called semiconservative because one old strand is conserved, and one complementary new strand is made. complementary

15. There are many origins of replication in eukaryotic chromosomes. Replication is fast and accurate. • DNA replication starts at many points in eukaryotic chromosomes. • DNA polymerases can find and correct errors.