DNA Replication - PowerPoint PPT Presentation

Loading...

PPT – DNA Replication PowerPoint presentation | free to download - id: 6fc32b-MzVlO



Loading


The Adobe Flash plugin is needed to view this content

Get the plugin now

View by Category
About This Presentation
Title:

DNA Replication

Description:

Title: DNA Replication Author: Cheryl Massengale Last modified by: Serena Created Date: 7/28/2005 4:25:42 PM Document presentation format: On-screen Show (4:3) – PowerPoint PPT presentation

Number of Views:156
Avg rating:3.0/5.0
Slides: 12
Provided by: Cheryl237
Category:

less

Write a Comment
User Comments (0)
Transcript and Presenter's Notes

Title: DNA Replication


1
DNA Replication
2
Replication Facts
  • DNA has to be copied before a cell divides
  • DNA is copied during the S or synthesis phase of
    interphase
  • New cells will need identical DNA strands why?

3
DNA Replication Step 1
  • Parent DNA prepares to replicate
  • Appears normal

4
DNA Replication Step 2
  • Enzyme Helicase unzips the DNA strand
  • Breaks the weak hydrogen bonds

5
DNA Replication Step 3
  • Two strands open forming Replication Fork
    (Y-shaped region)

Replication fork
6
DNA Replication Step 4
Helicase
  • DNA polymerase enzyme adds the new nucleotides
  • Enzyme proofreads and corrects mistakes
  • DNA polymerase initially makes about 1 in 10,000
    base pairing errors
  • The new error rate for DNA that has been
    proofread is 1 in 1 billion base pairing errors

Polymerase
7
DNA Replication Step 5
  • Replication is complete!
  • Result is 2 DNA molecules

8
(No Transcript)
9
Semiconservative Model of Replication
  • The two strands of the parental molecule
    separate, and each acts as a template for a new
    complementary strand
  • New DNA consists of 1 PARENTAL (original) and 1
    NEW strand of DNA

10
Question
  • What would be the complementary DNA strand for
    the following DNA sequence?
  • DNA -CGTATG-

11
Answer
  • DNA -GCGTATG-
About PowerShow.com