1. What stage of mitosis/meiosis does DNA replicate ?
Agenda for Tuesday May 1st
Go over making DNA
Go over DNA structure Worksheet
DNA replication
Quiz Tomorrow

2. Central Dogma

3. DNA replication DNA needs to replicate – creates new cells
These strands should be accurately copied and passed from parent cell to daughter cell
How are two daughter strands are created?

4. 3 theories of DNA replication
Conservative replication
Dispersive Replication
Semiconservative replication - how DNA replicates

6. Semiconservative Replication
Watson and Crick suggested semiconservative replication method
DNA separates, serve as templates, and produce DNA molecules that have one strand of parental DNA and one new strand of DNA
Occurs during interphase of mitosis and meiosis

7. 3 steps of replication
Unwinding
Base pairing
Joining

8. Unwinding DNA Helicase unwinds/unzips DNA strand
Hydrogen bonds are broken
Proteins bind to DNA to keep strands separate
RNA Primase adds a short starter segment to each strand

10. Base Pairing
Steps
DNA Polymerase catalyzes the addition of nucleotides to the new DNA strand
Always starts at 5’ and goes to 3’
Strands are identical (A=T, C=G)
Two strands are created in different ways
One is leading strand
One is the lagging strand

11. Leading Strand Replicated as the DNA unwinds
New nucleotides are added continuously

13. Lagging Strand Replicated away from replication fork
Create segments - Okazaki Fragment
New RNA Primer each time
Fragments are later connected

15. Joining
DNA polymerase comes to an RNA primer it removes primer and fills with DNA nucleotide
DNA Ligase links two sections of DNA together

17. Prokaryote vs. Eukaryote
Prokaryotes
1 origin
Eukaryote
Many origins

18. Replicate your DNA Put on a separate sheet of paper.
Discussion Questions
Compare the two new strands of DNA. Are they the same or different? Why?
2. How does the structure of a DNA molecule help account for the great variety of life that exists on earth?

20. SWEET VID!!

21. Questions
Answer questions 1-5 on page 335 in your book