320 likes | 452 Views
DNA Replication. Copying the genetic code. DNA Replication. Unpack the Chromosomes Unzip the DNA Base pairing at the replication fork Leading strand vs Lagging strand. Copying the genetic code. Making Copies. Making Copies. copied during cell division. copy.
E N D
DNA Replication Copying the genetic code
DNA Replication • Unpack the Chromosomes • Unzip the DNA • Base pairing at the replication fork • Leading strand vs Lagging strand Copying the genetic code
copied during cell division copy Sister Chromatids(identical copies)
Accessing the DNA DNA in use inactive DNA (deactivated or mitotic)
Visualization of DNA Packing • For this video, visit:http://www.hhmi.org/biointeractive/dna/DNAi_packaging_vo2.html
Replication Bubbles 3’ 5’ 3’ 5’ helicase
Replication Bubbles 3’ 5’ 3’ 5’
Replication Bubbles 3’ 5’ 3’ 5’
Replication Bubbles Replication Fork 3’ 5’ copies 3’ 5’ Replication Fork
Releasing the Tension • Topoisomerase cleaves and uncoils DNA ahead of helicase • Single-stranded DNA binding proteins (SSB) prevent DNA from coiling back up
DNA Replication Primase DNA Polymerase III 3’ 5’ RNA primer 3’ 5’
DNA Replication • The leading strands grow toward the replication fork 3’ 5’ Leading Strands 3’ 5’
DNA Replication 3’ 5’ 3’ 5’
DNA Replication • The lagging strands grow away from the replication fork 3’ 5’ Lagging Strands 3’ 5’
DNA Replication DNA Polymerase I DNA Ligase 3’ 5’ 3’ 5’
DNA Repliaction 3’ 5’ 3’ 5’
DNA Repliaction 3’ 5’ Okazaki Fragments 3’ 5’
The Whole Process in 3D • For this video, visit: • http://www.hhmi.org/biointeractive/dna/DNAi_replication_schematic.html
The Whole Process in 3D • For this video, visit: http://www.hhmi.org/biointeractive/dna/DNAi_replication_vo2.html