• 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
• 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’
• Site where DNA replication begins
• Replication Origins have many A’s and T’s
• _______y__dey__do___dat___doh_____
__________________________________
• an enzyme that breaks apart the hydrogen bonds
• unzips the double helix into single strands
• a small strand of RNA needed before the new
strand of DNA is written by _________________
• “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 _____
• the new strand created from the original 3’-> 5’ strand
• made 5’ -> 3’ continuously
• the new strand created from the backwards strand
• made 5’ -> 3’ interruptedly in short fragments
= Okazaki Fragments
• Ligase (“glue”) joins the fragments together
• 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