1. DNA & Replication Notes

2. DNA A.k.a. Deoxyribonucleic Acid Molecule present in all living cells
Contains information that determines the traits that an organism inherits and needs to live

3. Rosalind Franklin
Took one of the first photos of DNA using X-Ray Diffraction

4. Watson & Crick
Two scientists who discovered the structure of DNA as a double helix
Won a Nobel Prize for it
Maurice Wilkins also won nobel prize for DNA structure

5. DNA Structure

6. DNA Structure Double Helix Made up of nucleotides Twisted ladder
Nitrogenous base, phosphate, and sugar

7. DNA Structure Sides of ladder = alternating phosphates and sugars
Rungs of ladder = nitrogenous bases

8. 3D Model

9. DNA Picture

10. DNA Structure -Bases There are 4 nitrogenous bases Adenine (A)
Thymine (T)
Guanine (G)
Cytosine (C)

11. Nitrogenous Bases Certain bases match together
Guanine and Cytosine (C - G) pair together
“Good Couples”
Adenine and Thymine (A - T) pair together
“Always Together”

12. DNA Replication

13. DNA molecules are very long, nucleus of human cell has more than 1 meter of DNA.

14. DNA Replication
Each side of the DNA strand has all of the information needed to reconstruct the other half of the strand through the process of base pairing.
Due to this process (base pairing), the strands are said to be complementary.
DNA replication happens at hundreds of places along the strand- makes the process very fast!

15. Replication proceeds in both directions until each chromosome is completely copied.
Sites where separation and replication happen are called replication forks.

16. New Strand
Original strand
Nitrogen Bases
Replication Fork
Replication Fork
DNA Polymerase

17. Duplicating DNA
Replication- the copying process in which a cell duplicates its DNA, before it divides into 2 cells with complete sets of DNA molecules.

18. Step 1 --> Pull old DNA Apart
DNA molecule separates into two strands
DNA polymerase is the principle enzyme involved in DNA replication.
It pulls apart the old DNA strand so that each side can be copied
----- Meeting Notes (1/16/13 13:24) -----
ice cream

19. Step 2 --> Base Pairing
Bases are added to each side following the rules of base pairing.
Each strand of the double helix DNA serves as a template, or model, for the new strand.

20. Step 3 =RESULT
Result is two DNA molecules identical to each other and the original molecule.
Each DNA molecule from replication has one original strand and one new strand.

22. Replication Example

23. Replication Example

24. Replication Example

25. Real Chromosome Pictures!

26. Real Chromosome Pictures!

27. DNA Replication Video