1. 4/17 Daily Catalyst Pg. 55 Replication
1. A disease affects the body’s ability to generate hydrogen bonds. Explain the effect of this devastating disease on DNA.
2. Use the principle of complementary base pairing to find the complementary DNA pairs.
C C G A T A A G T A
3. What was the importance of add Dawn dish soap to the DNA mixture?

2. 4/17 Class Business Pg. 55 Replication
DNA test 4/23
Study guide due test
Review day on 4/22
DNA Extraction lab on Thursday
Be here! Labs are test grades!
Interims come out this Friday
Signed for extra credit due Monday

3. 4/17 Agenda Pg. 55 Replication
Daily Catalyst
Class Business
Replication notes
Replication video
Replication w.s.
Quiz #12 3

4. Recap… 3. What was the purpose of adding the DNA extraction buffer?
1. What are mutations?
Random changes in DNA
2. If there are 34% of Adenines in DNA, what is the percentage of uracil in RNA?
34%
3. What was the purpose of adding the DNA extraction buffer?
To break the nucleosome and unwind the DNA 4

5. DNA Recap… The building block of DNA is a nucleotide.
1 Phosphate group
1 Base
1 Sugar group
The sugar group is called deoxyribose
What does “deoxy” mean?
Without oxygen
The sugar group is missing an oxygen! 5

6. 4/17 Objective
Today we will be able to identify the process of replication and the key enzymes in replication.

7. What is an enzyme? Key Point #1: Enzyme
A protein that speeds up reactions!
Lowers the amount of energy needed to start the reaction

8. DNA DNA is very organized with specific nucleotide sequences.
Key Point #2:
The two strands of DNA have specific ends!
One end is labeled the 3’ end and the other end is the 5’ end.
The 2 sides of DNA bind 3’ to 5’ so the bases match up! 8

9. How do we pass DNA onto our children?
Turn and talk to your neighbor for 30 seconds.
We pass on DNA through out gametes or the sex cells like the egg and sperm. Can we just give away the DNA? No! 9

10. Do we simply give our DNA to our children?!
No! We can’t give away our DNA. We need to keep a copy for ourselves!

11. Replication over view video clip

12. DNA is passed onto your children first by duplicating the DNA.
Key Point #3:
DNA is copied in the nucleus in the process of replication.
Why in the nucleus? DNA stays in the nucleus for protection.
Why the copy machine? 12

13. Replication Graphic organizer
Step 1:
Replication Graphic organizer
Enzyme Helicase unzips DNA
DNA Polymerase adds new nucleotides to the 3’ end
DNA ligase glues the DNA fragments together
DNA ligase and polymerase proofread new DNA

14. Replication Step 1: DNA is unzipped.
The enzyme helicase unzips the DNA.
The 2 strands now act as templates for future DNA.
Templates? This is a pattern for future DNA. Like a cookie cutter.
Remind students that step #1 goes in the first box. 14

15. Replication Graphic organizer
Step 1:
DNA is unzipped.
The enzyme helicase unzips the DNA.
Replication Graphic organizer
Step 2:
Enzyme Helicase unzips DNA
DNA Polymerase adds new nucleotides to the 3’ end
DNA ligase glues the DNA fragments together
DNA ligase and polymerase proofread new DNA

16. Replication
Step 2:
Once the DNA has been unzipped, the enzyme DNA polymerase adds new nucleotides to the 3’ end only!!! 16

17. Replication Graphic organizer
Step 1:
DNA is unzipped.
The enzyme helicase unzips the DNA.
Replication Graphic organizer
Step 2:
the enzyme DNA polymerase adds new nucleotides to the 3’ end only!!!
Step 3:
Enzyme Helicase unzips DNA
DNA Polymerase adds new nucleotides to the 3’ end
DNA ligase glues the DNA fragments together
DNA ligase and polymerase proofread new DNA

18. AWWWW!
How does DNA Polymerase know which nucleotides to add???
Oh YA! Complementary base pairing!

19. Key Point #4: DNA polymerase, uses the old strand as a template for the new strand so it knows what new bases to add (base pairing).

20. What base will come next?

21. Template video clip

22. Semi-Conservative Model
The 2 parent strands act as templates for 2 new daughter strands.
When the DNA replicates, one of the strands will be the parent strand and from the parent strands the correct bases will be added making a new daughter strand.
Key Point #5: Semi-conservative model-
Half of the DNA is the old parent DNA and the other half is the new daughter DNA strand.
Where have we seen the root word semi? Semi –permeable and what does semi mean? It means halfway.
What does the word conservative mean? Conservative means staying the same. Half of the DNA is the old parent DNA and the other half is the new daughter DNA strand. 22

23. Semi:
Partially
Conservative:
Lack of change
The new DNA will have one “old” parent strand and one “new” daughter strand. This is how your parents pass on their characteristics to you.

24. Replication
Humans have over 6 billion base pairs, but it only takes a few hours to replicate all of them.
How do cells do this so quickly??!
DNA polymerases can replicate at multiple DNA sites.
Think of the St. Charles street car. They work on multiple parts of the track at once.
Right now they are fixing the street car. Do they only fix one part of the track at a time? No, that is not efficient. They fix multiple parts of the track at a time. This is the same as DNA. DNA polymerase replicates multiple DNA sites at a time. The enzyme DNA ligase will glue all of these pieces together. 24

25. Replication Graphic organizer
Step 1:
DNA is unzipped.
The enzyme helicase unzips the DNA.
Replication Graphic organizer
Step 2:
the enzyme DNA polymerase adds new nucleotides to the 3’ end only!!!
Step 3:
Enzyme Helicase unzips DNA
DNA Polymerase adds new nucleotides to the 3’ end
DNA ligase glues the DNA fragments together
DNA ligase and polymerase proofread new DNA

26. DNA Ligase glues all of the DNA pieces together. Glue?
Step 3:
DNA Ligase glues all of the DNA pieces together.
Glue?
By glue I mean forms Phosphodiester bonds that hold the nucleotides together.

27. Replication Graphic organizer
Step 1:
DNA is unzipped.
The enzyme helicase unzips the DNA.
Replication Graphic organizer
Step 2:
the enzyme DNA polymerase adds new nucleotides to the 3’ end only!!!
Step 3:
DNA Ligase glues all of the DNA pieces together.
Enzyme Helicase unzips DNA
DNA Polymerase adds new nucleotides to the 3’ end
DNA ligase glues the DNA fragments together
DNA ligase and polymerase proofread new DNA
Step 4:

28. Replication
After the new DNA pieces have been glued together, is the DNA ready?
Do you write an essay and turn it in on the first try?
NO! We proofread the essay first.
This is the same for DNA
Step 4:
DNA polymerase and DNA ligase proofread the DNA and repair any mistakes in base pairing. 28

29. Replication Graphic organizer
Step 1:
DNA is unzipped.
The enzyme helicase unzips the DNA.
Replication Graphic organizer
Step 2:
the enzyme DNA polymerase adds new nucleotides to the 3’ end only!!!
Step 3:
DNA Ligase glues all of the DNA pieces together.
Enzyme Helicase unzips DNA
DNA Polymerase adds new nucleotides to the 3’ end
DNA ligase glues the DNA fragments together
DNA ligase and polymerase proofread new DNA
Step 4:
DNA polymerase and DNA ligase proofread the DNA and repair any mistakes

30. Proofreading G A

31. Recap… That was a lot of information! Let’s put it all together!
What is the purpose of replication?
The purpose is to duplicate DNA
What is the end product of replication?
Two new strands of DNA
One strand to keep for yourself and one to give to your offspring 31

32. Take one minute to answer the following questions with a partner in your notebook.
1. Name the 3 essential enzymes for replication.
2. Describe the semi-conservative model.
3. Why is this model important to DNA?
I will be coming around to review your answers. This is like your exit ticket out of class today. 32

33. 1. Name the 3 essential enzymes for replication.
DNA helicase, polymerase, and ligase
2. Describe the semi-conservative model.
The parent strand acts at the model for the new daughter strand so the bases know how to pair up with another
3. Why is this model important to
DNA?
This is important because we need to keep our DNA and make an exact copy of our DNA to pass onto our children.

34. Quiz #12
Directions: silently and independently complete quiz #12. Turn the quiz into the basket when you are finished.
Time: 15 minutes
Noise: 0 (SILENT)

35. 4/17 Homework
Directions: Complete pages 3 of the DNA packet. This is DNA replication.
I will check these pages on Monday
Time: until the end of class
Noise: 1 (with partner)