DNA Replication

Replication step 1:

DNA unwinds at origin of replication

Replication step 2:

Helicase opens up the DNA forming replication fork

Replication step 3:

Single strand binding (ssb) proteins coat DNA around replication fork to prevent rewinding

Replication step 4:

Topoisomerase binds at the region, ahead of replication fork to prevent supercoiling

Replication step 5

primase synthesizes RNA primers complementary to DNA strand

replication step 6

DNA polymerase III starts adding nucleotides to the 3’-OH end of primer

lagging strand replication 1

primase joins RNA nucleotides into a primer

Lagging strand replication 2

DNA polymerase III synthesizes DNA forming okazaki fragments

Lagging strand replication 3

after reaching the next RNA primer to the right DNA pol III detaches

Lagging strand replication 4

okazaki fragment 2 is primed then DNA pol III adds nucleotides and detaches when reached fragment 1

Lagging Strand replication 5

DNA Pol I replaces RNA w DNA adding nucleotides to the 3’ end of fragment 1

Lagging strand Replication 6

DNA ligase forms a bond between the newest DNA and the DNA fragment 1

Lagging strand replication 7

The lagging strand in the region is complete