1. Agenda 4/23 and 4/24 DNA replication and protein synthesis review
Central Dogma Posters
Homework
1. DNA replication video and notes
2. Protein Synthesis Video and Notes

2. Central Dogma

3. DNA Replication
DNA replication is used to create new DNA before cell division
Semi-conservative replication is used
One side of ‘old’ DNA is used to create the ‘new’ side of DNA
DNA replication depends on complementary base pairing
Guanine-Cytosine
Thymine-Adenine

4. Meselson and Stahl Experiment

5. Enzymes of DNA Replication
1. Helicase- unwinds the double helix by breaking the hydrogen bonds between two bases
2. DNA polymerase- links nucleotides together to form a new strand using the pre-existing strand as a template

6. Transcription
Transcription is the synthesis of mRNA copied from a DNA template
RNA Polymerase ‘reads’ the DNA and pairs mRNA nucleotides using base pair rules
Adenine-Uracil
Guanine-Cytosine
Thymine-Adenine
Occurs in the nucleus of eukaryotic cells

7. Translation Synthesis of polypeptides on ribosomes
Amino acid sequence is determined by mRNA sequence
Codons of 3 bases of mRNA code for 1 amino acid
The tRNA carries the correct amino acid and will base pair with mRNA to create the polypeptide chain

8. Use of a codon chart
If the DNA sequence is ATGCCCGGA, what would the mRNA sequence be?
What would the amino acid sequence be?

9. Overview Posters 1. DNA replication 2. Transcription 3. Translation
Sample DNA sequence (at least 15 letters)
Semi-conservative nature
Helicase
DNA polymerase
Hydrogen bonds, anti-parallel structure, sugar-phosphate backbone, nitrogen bases
Complementary base pairing
2. Transcription
Location
RNA polymerase
Sugar-phosphate backbone
3. Translation
Location in cell
mRNA codon
tRNA anticodon
Peptide Bonds
Ribosome
Amino acids