PROMOTER REGION REGION TRANSCRIPTION REVIEW RNA POLYMERASE

POLYMERASE = WRITER

S Phase: Synthesis of DNA DNA REPLICATION

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

5’ 3’ DIRECTIONALITY OF DNA STRANDS 3’ 5’

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’

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

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 _____

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’

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

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