1 / 8

DNA Replication

DNA Replication . DNA Replication Facts. DNA Replication: DNA = Only known molecule that can replicate itself Structure explains how it easily replicates Each molecule has information needed to reconstruct the other side

shiri
Download Presentation

DNA Replication

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. DNA Replication

  2. DNA Replication Facts • DNA Replication: • DNA = • Only known molecule that can replicate itself • Structure explains how it easily replicates • Each molecule has information needed to reconstruct the other side • DNA molecules separates into 2 strands & produces 2 new identical strands (follows base pair rules) • DNA serves as model for new DNA strands

  3. DNA Replication Facts cont. • DNA Replication cont. • Occurs in S (Synthesis) phase of cell cycle • Chromosome #’s are being doubled = DNA is being replicated • Genetic material is going from 1 copy to 2 copies • Each new daughter cell will have exact same copy of DNA • Very rapid & accurate (only 1 in 1 Billion base-pairing errors) process

  4. DNA Replication • Process of DNA Replication: • Begins at Origins of Replication • Enzyme Helicase unwinds & separates 2 DNA strands – breaks the weak hydrogen bonds • Single-Strand Binding Proteins attach & keep 2 DNA strands separated & untwisted • 2 strands open forming Replication Forks (Y-shaped) • New strands grow at the forks

  5. DNA Replication cont. • Process of DNA Replication cont: • RNA Primers add new nucleotides to help form new DNA strands • Correct bases are added to each side of the backbone (ladder) • A -- T & C -- G • Sugar-phosphate backbone links are added to extend the backbone (ladder)

  6. DNA Replication cont. • Proofreading the new DNA: • Enzyme - DNA polymerase proofreads new DNA strand to make sure base pairing is correct • If error is found – polymerase will cut, remove & correct the mistake = Excision Repair • Error rate after proofreading = 1 in 1 billion base pairing errors • Now have 2 identical DNA strands!!

  7. DNA Template Parental DNA Molecule Replication Fork Parental DNA RNA Primer New DNA DNA Polymerase Nucleotides DNA Replication (Draw these!) Helicase S.S.B.P

  8. DNA Replication Review • DNA Replication Review: • DNA is unzipped (by Helicase) • DNA strands held open by (Single-Stranded Binding Proteins) • RNA Primers add new nucleotides • Sugar-phosphate links are added • DNA polymerase proofreads new DNA strands • Fixes any errors = Excision Repair • Two new identical DNA strands

More Related