1 / 15

DNA replication

DNA replication. DNA Video. DNA = Deoxyribonucleic Acid. Importance of DNA Molecule that stores genetic information in living cells Produces proteins by coding for different amino acids Proteins are involved in EVERY life process. Structure of DNA. DNA is a polymer of nucleotides

amity-garrett
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 Video

  3. DNA = Deoxyribonucleic Acid • Importance of DNA • Molecule that stores genetic information in living cells • Produces proteins by coding for different amino acids • Proteins are involved in EVERY life process

  4. Structure of DNA • DNA is a polymer of nucleotides • These nucleotides have three parts: • Simple sugar: deoxyribose • Nitrogen bases: A, T, C, G • Phosphate group

  5. Structure of DNA • There are four nitrogen bases: • A = adenine T = thymine • G = guanine C = cytosine • Which bases are complementary to each other? • A with T • G with C

  6. Structure of DNA • DNA is shaped like a double helix • Looks like: spiral staircase or twisted ladder • Sides = Phosphate groups and sugars • Steps or rungs = Nitrogen bases • Bases are held together by weak hydrogen bonds

  7. Structure of DNA

  8. Discovery of DNA shape • James Watson and Francis Crick discovered the double helix shape in 1953 • Discovery was based on major research by Rosalind Franklin

  9. How DNA works • The sequence of bases code for different amino acids • These chains of amino acids make proteins • Set of 3 bases that code for an amino acid is called a codon • ATG + CGG + CTA  protein • Amino acid + amino acid + amino acid  protein Tyrosine Alanine Aspartate

  10. How DNA works

  11. DNA Replication • What is it? Process by which chromosomal DNA is copied before mitosis and meiosis • When does it happen? Interphase

  12. DNA Replication • Why does it happen? To allow cells to maintain the appropriate amount of genetic information Meiosis – each cell gets half the genetic information as the original cell • Mitosis – each cell gets the same genetic information as the original cell 2n 2n 1n 1n 2n 2n 1n 1n 1n 1n

  13. Steps of DNA Replication • Strands of DNA Separate: Hydrogen bonds between bases are broken by an enzyme and the strands separate • Base Pairing: Free-floating nucleotides pair up with bases on the exposed strand (matches with the complementary base – AT & CG)

  14. Steps of DNA Replication • Bonding Nucleotides Backbone (sugar/phosphates) of the once-free nucleotides are bonded together by an enzyme to form a new complementary strand • Result of Replication Two DNA molecules, each with a new strand and an old strand

  15. DNA Replication • http://my.hrw.com/tabnav/controller.jsp?isbn=0030931401 http://my.hrw.com/tabnav/controller.jsp?isbn=0030931401

More Related