DNA
 Double stranded
 Complimentary
 Composed of
Nucleotides
DNA replication
 DNA Helicase – breaks
hydrogen bonds holding
complimentary strands
together
 Forms replication fork
 Leading strand
 Lagging strand
DNA Replication
DNA is read 5’ to 3’
Leading Stand
 Helicase -> RNA pimase -> DNA polymerase
Lagging Stands
 Helicase -> RNA primase -> DNA polymerase -> okazaki fragments ->
DNA polymerase cleans up RNA primase strand -> DNA ligase
Movie
 Replication
 http://highered.mcgrawhill.com/sites/0072943696/student_view0/chapter3/ani
mation__dna_replication__quiz_1_.html
 http://www.hhmi.org/biointeractive/dna-replicationadvanced-detail
Protein
Synthesis
2 parts
 Transcription

To copy segment of
DNA
 Translation

To translate the
language of
nitrogenous bases into
amino acids
RNA vs. DNA
 Difference between mRNA and DNA



Single stranded vs. Double stranded
The sugar has an extra oxygen, ribose vs. deoxyribose
Uses uricil “U” instead of thymine
Transcription
 Production of mRNA
 RNA primase binds to DNA at a promoter region
 RNA polymerase adds bases copying the gene
Movie
 Transcription
 http://www.dnalc.org/resources/3d/13-transcriptionadvanced.html
Packaged
 mRNA is processed to leave the nucleus



Extras are cut out
 Splicosomes
 Introns
 Exons
Poly-A tail
5’ cap
Translation
 mRNA has left the nucleus.
 Binds with ribosome
 mRNA -> tRNA -> amino acids -> folded proteins
 What’s the Problem?
 mRNA

UGGCUUGCAUGCCGGAGUCCACGUAAUCA
Into
 Amino acids
AG
UC
Amino Acids
Translation
 tRNA consists of a
 Anticodon – 3 bases that match codon
 Amino acid
 Codon – 3 base sequence on
mRNA
Translation
 mRNA -> tRNA -> amino acids -> proteins
Translation
 mRNA
 UGGCUUGCAUGCCGGAGUCCACGUAAUCA
Movie
 Translation
 http://www.hhmi.org/biointeractive/translation-basicdetail