1. DNA Replication

2. 1. What does it mean to replicate?
Replicate means to duplicate or copy.

3. DNA Replication Summary
When one DNA molecule is duplicated (copied) to make two new molecules DNA. Start with one molecule of DNA. End with two new molecules of DNA. Exact Copies

4. What organisms Go through DNA Replication?
All living things go through DNA Replication.

5. Why would your cells need to make copies of its DNA?
Purpose
Why would your cells need to make copies of its DNA?

6. Purpose of DNA Replication
DNA replication occurs when new or more cells are needed. - Asexual (mitosis) Examples: -Sexual (meiosis) Everything in the cell is replicated- including DNA

7. DNA Replication: Step by Step
3 steps to DNA replication
Unzip/Separate
Building/Adding
2 New Copies
Some steps require enzymes (proteins) to speed up the process

8. DNA Replication in Real Time
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9. Step One: Separate or Unzip
Description: DNA is separated into two strands Materials: An enzyme: DNA Helicase “unzips” the DNA

10. Step Two: Building
Description: Nucleotides are added to the both of the two separated strands Two Materials: -A. An enzyme: DNA Polymerase adds nucleotides to the old strand. -B. Free Nucleotides

11. Step Three: New Copies
Description: Two new copies (exact duplicates) are made.

12. Summary
Separate
Build
Two new copies

13. Which model of DNA replication do you think DNA goes through?

14. DNA Replication Model
DNA replication is known as semi-conservative What does “semi-” mean? -half or partial What does “conservative” mean? -using old materials, not changing

15. DNA Replication is Semi-Conservative because….
The 2 new molecules of DNA are each made of: -one old “parent” strand -one newly made “daughter” strand

16. Accuracy of replication
This replication process only makes a mistake once every billion nucleotides
DNA polymerase has a built in proofreader (spell-check) that checks for mistakes and fixes them immediately!

17. Which model of DNA replication do you think DNA goes through?

18. Table Chalk Review: Directions1. 2. 3.
Name the three steps
Draw a diagram
Label the “materials”
Show me to get credit
Step 3: Use different colors to show the difference between the parent strand and the new daughter strand of DNA