DNA Replication

DNA Replication

• In order to copy the DNA double helix, the DNA needs to unravel and expose the nucleotides.

• DNA Helicase is a protein that comes in, unlocks the base pairs and separates the strands.

DNA Polymerase

• Once the strands are separated, another protein called DNA polymerase attaches to the strands and begins attaching matching base pairs.

New base pairs being added

New base pairs being added

DNA Replication

DNA Helicase

DNA PolymeraseDNA Polymerase

Overview

DNA Replication

Binary Fission

• Prokaryotes (bacteria) reproduce by binary fission.

Bacteria• Step 1- replicate the single chromosome.

• Step 2- replicate the DNA plasmids

• Step 3- separate the two sister chromatids and the plasmids.

• Step 4- Begin pinching off the cell

• Step 5- Separate into two new bacteria

Chromosomes• A single long piece of DNA – wrapped up

and bound into a tight formation.

• Contains between 50-250 million base pairs

Humans have 23 pairs of Chromosomes (46 total)

Sister Chromatids- Duplicated identical pieces of DNA

After duplication, the two identical strands are now called Chromatids

Sister chromatids are held together by the

Human Chromosomes After Duplication

It takes _____ minutes to duplicate the DNA of one cell