2. PROMOTER REGION
REGION
TRANSCRIPTION REVIEW
RNA POLYMERASE

3. POLYMERASE =
WRITER

4. S Phase:
Synthesis of DNA
DNA REPLICATION

5. MANNER SEMI-CONSERVATIVE DNA IS REPLICATED IN A
In DNA Replication, the entire genome doubles; one double helix becomes two double helices
one original strand becomes the template for the new strand
each of the two double helices has an original strand and a new strand

6. 5’ 3’
DIRECTIONALITY OF
DNA STRANDS 3’ 5’

7. 5’ 3’ DNA STRANDS 3’ 5’ DIRECTIONALITY OF
DNA has 3’ (three prime) and 5’ ends
5’ has the phosphate tail 3’ has the carboxyl head
Strands are anti-parallel
DNA is read 3’ -> 5’
Copied strands are created 5’ -> 3’ 3’ 5’

9. ORIGIN OF REPLICATION Site where DNA replication begins
Replication Origins have many A’s and T’s
_______y__dey__do___dat___doh_____ __________________________________

10. Helicase RNA Primer DNA Polymerase
an enzyme that breaks apart the hydrogen bonds
unzips the double helix into single strands
RNA Primer
a small strand of RNA needed before the new strand of DNA is written by _________________
DNA Polymerase
“writer” enzyme *thingies ending in –ASE are enzymes
creates the new copied strand of DNA by adding on matching letters on the template
READS 3’ -> 5’ CREATES new strand from _____

11. LEADING STRAND 3’ 5’ 3’ LAGGING STRAND 5’
the new strand created from the original 3’-> 5’ strand
made 5’ -> 3’ continuously 5’ 3’
LAGGING STRAND
the new strand created from the backwards strand
made 5’ -> 3’ interruptedly in short fragments
= Okazaki Fragments
Ligase (“glue”) joins the fragments together 5’

12. ORIGIN OF REPLICATION the E. coli genome has ONE replication origin
the human genome has THOUSANDS

14. DNA polymerase initially makes about 1 in 10,000 base pairing errors
Various enzymes proofreads and corrects these mistakes
The new error rate for DNA that has been proofread is 1 in 1 billion base pairing errors
ERRORS
MUTATIONS