1. 12.2 Replication of DNA Objective:
5(A) Describe the stages of the cell cycle, including deoxyribonucleic acid (DNA) replication and mitosis, and the importance of the cell cycle to the growth of organisms.

2. 4(A) Compare and contrast prokaryotic and eukaryotic cells.
5(A) Describe the stages of the cell cycle, including deoxyribonucleic acid (DNA) replication and mitosis, and the importance of the cell cycle to the growth of organisms.
1(A) Demonstrate safe practices during laboratory and field investigations.
3(E) Evaluate models according to their limitations in representing biological objects or events.
4(A) Compare and contrast prokaryotic and eukaryotic cells.
4(B) Investigate and explain cellular processes, including homeostasis, energy conversions, transport of molecules, and synthesis of new molecules.
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Replication of DNA

3. Essential Questions
What is the role of enzymes in the replication of DNA?
How are leading and lagging strands synthesized differently?
How does DNA replication compare in eukaryotes and prokaryotes?
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Replication of DNA

4. Vocabulary Review New template semiconservative replication
DNA polymerase
Okazaki fragment
Replication of DNA
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5. Semiconservative Replication
During semiconservative replication, parental strands of DNA separate, serve as templates, and produce DNA molecules that have one strand of parental DNA and one strand of new DNA.
Process occurs in three main steps: unwinding, pairing, and joining.
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Replication of DNA

6. Semiconservative Replication
Unwinding
DNA helicase, an enzyme, unwinds the helix, breaking the hydrogen bonds between bases
Single-stranded binding proteins keep the DNA strands separate during replication.
RNA primase adds short segments of RNA primer, on each DNA strand.
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Replication of DNA

7. Semiconservative Replication
Base pairing
The enzyme DNA polymerase adds appropriate nucleotides to the new DNA strand from the 3’ end.
The leading strand is built continuously, the lagging strand is built discontinuously in small segments called Okazaki fragments.
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Replication of DNA

8. Semiconservative Replication
Joining
DNA polymerase removes the RNA primer and fills in the place with DNA nucleotides.
DNA ligase links the two sections.
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Replication of DNA

9. Comparing DNA Replication in Eukaryotes and Prokaryotes
Eukaryotic DNA unwinds in multiple areas as DNA is replicated.
In prokaryotes, the circular DNA strand is opened at one origin of replication.
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Replication of DNA

10. Review Essential Questions Vocabulary
What is the role of enzymes in the replication of DNA?
How are leading and lagging strands synthesized differently?
How does DNA replication compare in eukaryotes and prokaryotes?
Vocabulary
semiconservative replication
DNA polymerase
Okazaki fragment
Replication of DNA
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