1 / 9

DNA Review

DNA Review. What does DNA store that is important? If a DNA strand read AGT-CCG-GTA what would the complimentary strand read? What holds the nitrogen bases together? What are the 3 components of a nucleotide?. DNA Replication. DNA Replication- the process of making a copy of DNA

iola
Download Presentation

DNA Review

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 Review • What does DNA store that is important? • If a DNA strand read AGT-CCG-GTA what would the complimentary strand read? • What holds the nitrogen bases together? • What are the 3 components of a nucleotide?

  2. DNA Replication • DNA Replication- the process of making a copy of DNA • Why is this important? • Cells need to copy their DNA for mitosis (growth, repair, and maintenance) • Three steps: • Double helix unwinds and DNA helicase opens the strand • DNA polymerases add nucleotides back • Polymerases detach once replication is complete • You end with 2 stands of identical DNA strands

  3. DNA Replication Step 1: • The double helix must unwind before replication can begin. • DNA helicases are enzymes that open the double helix by breaking the hydrogen bonds that hold the complimentary bases together (think of a zipper) • Replication goes from 5’ to 3’

  4. DNA Replication Step 1 con’t: • Once separated, additional proteins hold the strands apart. • Where the double helix separates is called a replication fork (because of it’s Y shape)

  5. DNA Replication Step 2: • At the replication fork enzymes called DNA polymerases move along each of the DNA strands. • DNA polymerases add nucleotides to the exposed bases according to the base pair rules

  6. DNA Replication Step 3: • Step 2 continues until all DNA has been copied and the polymerases detach • Produces 2 DNA molecules that are identical to each other and the original strand

More Related