1. DNA
DNA spells

2. Bellringer
How are photosynthesis and the calvin cycle connected? How do they relate to glycolysis, citric acid, and ETC?

3. Nucleic Acids DNA – the genetic code for ALL proteins
RNA – the code for ONE protein
ATP - Energy
All are made of nucleotides

4. Eukaryotic DNA Structure
We have 46 strands of it – called chromosomes
23 from mom, 23 from dad
If it is damaged it can be:
Repaired by DNA polymerase
Cancer
Cell death

5. Prokaryotic DNA Structure

6. Prokaryotic DNA Structure
Nucleoid
Just one chromosome
Closed in a circular loop
Remember – these are very simple organisms with no lipid bound organelles – they don’t need the code for much

7. Viral Genetic material
Can be one small strand of DNA or several small strands
Can be 5,000 nitrogen bases or millions (we are billions long)
Can be:
Double stranded DNA
Single stranded DNA
Single stranded RNA
Double stranded RNA
Viruses are jerks and break all the rules 

8. Nucleotides Phosphate group – acts to hold the sugars together
Sugar – Deoxyribose in DNA, Ribose in RNA and ATP
nitrogen bases
Adenine, Guanine, Cytosine in both
Thymine in DNA
Uracil in RNA

9. The backbone of DNA Phosphates and sugars bind together
The bond between a sugar and a phosphate is called PHOSPHODIESTER BOND
5’ – 3’
Backbone protects nitrogen bases

10. Nitrogen bases Adenine and Guanine “Large” nitrogen bases
Purines
Pyrimidines
Adenine and Guanine
“Large” nitrogen bases
Adenine binds with thymine in DNA/ Uracil in RNA
Guanine binds with cytosine
Cytosine, Thymine, and Uracil
“Small” nitrogen bases
Cytosine binds with guanine
Thymine is only in DNA and binds with adenine
Uracil binds with adenine in RNA

11. Nitrogen bases
Purines
Pyrmidines

12. How do they bind? Covalent bond from sugar to nitrogen base
Hydrogen bonds connect nitrogen bases
This leads to two strands of DNA
The shape is called a DOUBLE HELIX

13. How did we find it out? NOT WATSON AND CRICK IT WAS A WOMAN
NO ONE EVER TALKS ABOUT HER AND IT MAKES ME SO ANGRY
ROSALIND FRANKLIN FO LYFE
DON’T TELL ME WHAT YOU CAN’T DO

14. How did we build what DNA looks like?
Watson and Crick thought purines bound to purines, and pyrimidines to pyrimidines
Rosalind Franklin knew it was bogus –the model didn’t fit
She took a sample of DNA and saw it was an even tube

15. Chargaff’s Rule
The percentage of nitrogen bases must equal their complements
By knowing the percentage or amount of one nitrogen base you can find all others
Example:
If you find that an animals has 30.3% adenine, what are its concentrations of: G C T

16. DNA Replication In organic chemistry we number the carbons
This lets us show which carbons are bonded
Deoxyribose sugar can bind to phosphates at the 5’ or 3’ carbon
THIS DETERMINES THE SHAPE OF DNA

17. DNA Replication
Antiparallel elongation – the two strands run paralell, but in opposite directions
One goes from 5’3’ while the other goes 3’5’
The enzyme which replicates DNA can only go from 3’ to 5’
…what about the 5’3’ strand?

18. Strands
Leading Strand
Lagging Strand
3’5’
Has one primase added and DNA Polymerase III is able to continue unhindered
5’3’
Is going against the grain
Requires several primases
Contains okazaki fragments

19. Enzymes for laggers AND leaders
Helicase – unwinds the DNA by cutting the hydrogen bonds between nitrogen bases
Single – Strand Binding Proteins – hold the DNA open after the strands are split
Topoisomerase – relieves the tention caused by unwinding DNA

20. Enzymes
Leading Strand
Lagging Strand
Primase – adds the RNA primer at the 5’ end so replication can begin
DNA Pol III – continuously synthesizes the leading strand from 3’-5’
DNA pol I – removes primer from 5’ end and replacing it with DNA
DNA Ligase – joins the 3’ end added by DNA pol I to the leading strand added by DNA pol III
Primase – adds the RNA primer at the 5’ end of each okazaki fragment
DNA Pol III – elongates each okazaki fragment
DNA pol I – Replace primers with DNA
DNA Ligase – Joins okazaki fragments

21. Leading and Lagging strands
One runs on the 3’5’ TEMPLATE strand adding a NEW 5’3’ strand
Going in the other direction polymerase can’t create one large strand, instead it makes fragments called okazaki fragments

22. Replication Fork

23. Lets put this in perspective…
Helicase cuts the hydrogen bonds. Topoisomerase relieves the tension. SSBP’s hold it open
Primase adds a primer of RNA that signals DNA Polymerase III to attach and add nucleotides in a 5’3’ direction to the 3’5’ template
DNA Pol I removes the RNA primer and replaces it with DNA
DNA Ligase binds the gaps together

24. How is DNA repaired? DNA is mismatched. How can we fix it?
Nuclease cuts out the bad section
DNA Pol III puts in the right nucleotides
Ligase stiches the new chunk to the old

25. Aging Each time DNA replicates a strand shortens.
DNA polymerase can’t start with a 3’ end. It must start at the 5’ template end.
This causes a shortened end.
Telomerase can lengthen the strand back to its original length but is not normally active.
It IS however active in cancer cells, they reproduce forever

26. Aging