1. The Quick and Dirty Review of DNA

2. Deoxyribonucleic Acid
DNA is composed of subunits called nucleotide.
A DNA nucleotide has three parts:
Phosphate
5-Carbon Sugar
Nitrogenous Base
Adenine
Thyamine
Guanine
Cytosine

3. Structure Double Helix (aka The twisted ladder) Rungs= Bases
Sides= alternating phosphates and sugars.
Hydrogen bonds hold the 2 strands together
Follows base pairing rules:
A – T
C-G

4. Replication Goal is to make exact copy of DNA.
In summary, the DNA unwinds and separates. Enzymes read one side and make a complimentary sequence using free nucleotides. The same process happens on the other side.

5. Using DNA
The information in DNA is used to make proteins.

6. DNA vs. RNA

7. The Steps to Make a Protein
Transcription
Occurs in the nucleus
Translation
Occurs at the ribosome

8. Transcription (DNA  mRNA)
DNA pulls apart
RNA polymerase make a complimentary mRNA sequence to one side of the DNA molecule.
Once entire gene is copied, DNA strands bond back together and mRNA goes off to the ribosome.

9. Translation (mRNA  Protein)
mRNA binds to ribosome.
Ribosome starts reading at the start codon AUG
tRNA’s bring the amino acid over to the ribosome.
The process continues until a stop codon has been reached.

10. Example Problem DNA: TACGGTACGCTG mRNA: AUG-CCA-UGC-GAC
Protein: Methionine-Proline- cysteine-aspartate

11. Mutations Chromosomal Mutations Large amount of DNA are effected.
Gene mutations
Only affects a one or a few nucleotides
Also called point mutations
Deletions/Insertions
Substitutions
Mutation may cause different outcome
Frameshift
Many amino acids are wrong
Early Stop
Incomplete protein
Silent
No Change in the protien
Missense
1 amino acid is different
Chromosomal Mutations
Large amount of DNA are effected.
Inversion
Translocations
Large scale addition/deletions
Duplications
Many genes are messed up