Book of LifeDNA & Protein Synthesis

Ch10

Nucleic Acids• DNA

• RNA

• ATP

Where is DNA located? Hammerling & acetabularia expt.

Questions of the Day• Is heredity info. Protein or DNA?

– Griffith & Avery • Transforming principle

– Hershey & Chase• Bacteriophage experiments

• What is the structure of DNA?– Watson & Crick – essential structure– Rosalind Franklin

• X-ray chrystallography

• How does it work?

Bonding

• Sugar/phosphate “poles”

• N- base pairs

DNA is “nice”• Complementary Base Pairing

–Chargaff’s rule• #A = #T

• #C = #G

Replication

• Making a copy (synthesizing new DNA)

– Always attach at 3’ end• Towards replication fork

• Away from fork in “chunks”

– each new cell made has an exact copy of the original DNA from the parent cell

Enzymes help speed up the process

• Helicase

• DNA Polymerase

• Ligase

No Mistakes allowed!!

• “Typo’s” or mutations occur

• Proofreading enzymes repair mutations

• Only 1 error/billion nucleotides allowed

Mutations & Genetic Traits

• Sequences of DNA codes make up genes

• Any change to the code changes the gene

• Any change to the gene changes what we see in our phenotype