1 / 31

Nucleic Acids

Information storage. Nucleic Acids. 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. DNA. 1.

paniz
Télécharger la présentation

Nucleic Acids

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. Informationstorage NucleicAcids

  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. DNA 1 Synthesis of mRNA in the nucleus mRNA NUCLEUS CYTOPLASM mRNA 2 Movement of mRNA into cytoplasm via nuclear pore Ribosome 3 Synthesis of protein Aminoacids Polypeptide DNA RNA protein: information flow in a cell

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

  5. 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?

  6. SPECIAL NOTE • A NUCLEOSIDE is a precursor to a NUCLEOTIDE. It contain ONLY a nitrogenous base and a sugar – NO PHOSPHATE

  7. Types of nucleotides Purine = PURE As Gold Pyrimidines= CUT the PY • 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)

  8. Formation of a nucleic polymer • DEHYDRATION SYNTHESIS AGAIN!!!! • A bond forms between the adjoining nucleotides and is assisted by polymerases • A backbone of S-P-S-P-S- etc. is formed

  9. DNA Synthesis • A new strand of DNA is synthesized in the 5' to 3' direction • There a 3’ end must be open to elongate • NOTE: It is read by RNA from the 3’ to 5’ end

  10. 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

  11. Breaking down into Monomers • HYDROLYSIS AGAIN!!! • Bonds between the adjacent nucleotides are destroyed within the nucleic acid polymer.

  12. 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?

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

  14. A brief, explanatory film strip

  15. 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?

  16. 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

  17. 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)

  18. 1953 | 1962 Watson and Crick … and… Crick Watson

  19. Maurice Wilkins… and… 1953 | 1962

  20. Rosalind Franklin (1920-1958)

  21. X-raydiffraction pattern Photographic film Diffracted X-rays X-raysource X-ray beam Crystal Nucleic acid Protein (a) X-ray diffraction pattern (b) 3D computer model X-ray crystallography

  22. James Watson Describes the Moment

  23. 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)

  24. Another interesting note… • ATPAdenosine triphosphate • modified nucleotide • adenine (AMP) + Pi + Pi + +

  25. You should now be able to: • List and describe the four major classes of molecules • Distinguish between the following pairs: pyrimidine and purine, nucleotide and nucleoside, ribose and deoxyribose, the 5’end and 3’ end of a nucleotide

  26. Macromolecule Review

  27. Carbohydrates • Structure / monomer • monosaccharide • Function • energy • raw materials • energy storage • structural compounds • Examples • glucose, starch, cellulose, glycogen glycosidic bond

  28. Lipids • Structure / building block • glycerol, fatty acid, cholesterol, H-C chains • Function • energy storage • membranes • hormones • Examples - fat, phospholipids, steroids • NOT POLYMERS (No repeating units) ester bond (in a fat)

  29. Proteins • Structure / monomer • amino acids • levels of structure • Function • enzymes u defense • transport u structure • signals u receptors • Examples • digestive enzymes, membrane channels, insulin hormone, actin peptide bond

  30. Nucleic acids • Structure / monomer • nucleotide • Function • information storage & transfer • Examples • DNA, RNA • Modified Nucleotide: ATP phosphodiester bond

More Related