html5-img
1 / 17

Introduction to DNA & RNA

Unit 2: Molecular Genetics Bi 1d: Central Dogma Bi 5a: DNA, RNA, protein structure and function Bi 5b: Base pairing rules. Introduction to DNA & RNA. proteins. DNA. Nucleic Acids. Function: genetic material stores information genes blueprint for building proteins

caspar
Download Presentation

Introduction to DNA & RNA

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. Unit 2: Molecular Genetics Bi 1d: Central Dogma Bi 5a: DNA, RNA, protein structure and function Bi 5b: Base pairing rules Introduction to DNA & RNA

  2. proteins DNA Nucleic Acids • Function: • genetic material • stores information • genes • blueprint for building proteins • DNA  RNA  PROTEINS • transfers information • blueprint for new cells • blueprint for next generation

  3. Nucleic Acids • Examples: • RNA (ribonucleic acid) • single helix • DNA (deoxyribonucleic acid) • double helix • Structure: • monomers = nucleotides DNA RNA

  4. Nucleotides • 3 parts • nitrogen base (C-N ring) • pentose sugar (5C) • ribose in RNA • deoxyribose in DNA • phosphate(PO4)group Nitrogen baseI’m the A,T,C,G or Upart! Are nucleic acidscharged molecules?

  5. Types of nucleotides Purine = AG Pure silver! • 2 types of nucleotides • different nitrogen bases • purines • double ring N base • adenine (A) • guanine (G) • pyrimidines • single ring N base • cytosine (C) • thymine (T) • uracil (U)

  6. Building the polymer

  7. Nucleic polymer • Backbone • sugar to PO4 bond • phosphodiester bond • new base added to sugar of previous base • polymer grows in one direction • N bases hang off the sugar-phosphate backbone

  8. Pairing of nucleotides • Nucleotides bond between DNA strands • H bonds • purine :: pyrimidine • A :: T • 2 H bonds • G :: C • 3 H bonds Matching bases?Why is this important?

  9. DNA molecule • Double helix • H bonds between bases join the 2 strands • A :: T • C :: G H bonds?Why is this important?

  10. Copying DNA • Replication • 2 strands of DNA helix are complementary • have one, can build other • have one, can rebuild the whole Matching halves?Why is this a good system?

  11. When does a cell copy DNA? • When in the life of a cell does DNA have to be copied? • cell reproduction • mitosis • gamete production • meiosis

  12. DNA replication “It has not escaped our notice that the specific pairing we have postulated immediately suggests a possible copying mechanism for the genetic material.” James Watson Francis Crick 1953

  13. Rosalind Franklin (1920-1958)

  14. Chargaff 1947 • DNA composition: “Chargaff’s rules” • varies from species to species • all 4 bases not in equal quantity • bases present in characteristic ratio • humans: A = 30.9% T = 29.4% G = 19.9% C = 19.8% RulesA = T C = G That’s interesting!What do you notice?

  15. Interesting note… • Ratio of A-T::G-C affects stability of DNA molecule • 2 H bonds vs. 3 H bonds • biotech procedures • more G-C = need higher T° to separate strands • high T° organisms • many G-C • parasites • many A-T (don’t know why)

  16. The “Central Dogma”( put this on your composition notebook right after the Homework) • Flow of genetic information in a cell Where do these processes occur in the cell? transcription translation DNA RNA protein replication

  17. DNA vs RNA(on your composition notebook after “Central Dogma”)

More Related