AP bio unit 6

Orgin of replication

Specific sites that move short stretches of DNA with a specific nucleotide sequence coding for replication to begin

Unwinding

At the replication fork at each end of a replication bubble where the parental strands are being unwound by proteins

Proteins that help unwind

Helicases are enzymes that untwist the helix and single strand binding proteins bind to unwound and unpaired DNA strands to keep them from repairing

Synthesis

DNA polymerase adds nucleotide to the primer, forming an Okazaki fragment

Antiparallel elongation

Each DNA strand can only replace in one direction. DNA polymerase can only add to the 3’ end

2 strands leading

The leading strand is then made from the addition of nucleotides in a 5’ to 3’ direction. On this strand DNA synthesis occurs continuously

2 strands lagging

The lagging strand is added in a direction away from the replication fork because DNA polymerase can only add to the 3’ end. The strand allows for the synthesis of Okazaki fragments.

Process copying DNA exactly

This process is made to copy DNA exactly because DNA contains a sequence of nucleotides that is exactly complementary to the partner strand