12-2
Upcoming SlideShare
Loading in...5
×
 

12-2

on

  • 447 views

DNA replication

DNA replication

Statistics

Views

Total Views
447
Views on SlideShare
447
Embed Views
0

Actions

Likes
2
Downloads
50
Comments
0

0 Embeds 0

No embeds

Accessibility

Categories

Upload Details

Uploaded via as Microsoft PowerPoint

Usage Rights

© All Rights Reserved

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Processing…
Post Comment
Edit your comment

12-2 12-2 Presentation Transcript

  • 12-2 chromosomes and DNA replication• DNA: – Prokaryotic cell: • Naked, in cytoplasm, no nucleus • Single circular DNA • No complex with histone Bases on the chromosome – eukaryotic cell: • In nucleus, • In the form of chromosome Chromosome E. coli bacterium
  • • Chromosome structure: – Chromatin : DNA + proteins – Chromosome : supercoiled chromatin – Nucleosome • beadlike structures in chromosome formed by DNA and histone molecules • Help to fold long DNA into tiny cell nucleus Chromosome Nucleosome DNA double helix Coils Supercoils Histones
  • • DNA replication (in interphase of mitosis or meiosis) – Prokaryotic cell: • Begins at a single point • Proceeds in two directions
  • • DNA replication (in interphase of mitosis or meiosis) – Eukaryotic cell: • Begins at many sites • Proceeds in two directions
  • • DNA replication – Semi-conservative replication • During DNA replication, the DNA double helix separates into two strands. Each strand serves as a template to produces two new complementary strands following the rules of base pairing. Parent DNA Copy
  • • DNA replication – Steps • Unzip (form replication fork) • Strands assembled in the 5’ to 3’ direction (Continuous and Discontinuous, form okazaki fragments) • 2 identical DNA molecules replication forkAHL
  • AHL
  • • DNA replication – Enzyme envolved Helicase: unzips DNA. Primase: add short RNA primers. Single-strand binding protein : hold seperated strands apart DNA polymerase : DNA polIII: attaches complementary nucleotides & proofreading DNA pol I: replaces RNA primers with DNA nucleotides. DNA ligase: seal okazaki fragmentsAHL
  • AHL