1. AP Biology 2006-2007 Nucleic Acids Information storage

2. AP Biology 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  carries energy

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

4. AP Biology Nucleic Acids  Examples:  RNA (ribonucleic acid)  single helix  DNA (deoxyribonucleic acid)  double helix  Structure:  monomers = nucleotides RNADNA

5. AP Biology Nucleotides  3 parts  nitrogen base (C-N ring)  pentose sugar (5C)  ribose in RNA  deoxyribose in DNA  phosphate (PO 4 ) group Are nucleic acids charged molecules? Nitrogen base I’m the A,T,C,G or U part!

6. AP Biology Types of nucleotides  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)

7. AP Biology Nucleic polymer  Backbone  sugar to PO 4 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. AP Biology Pairing of nucleotides  Nucleotides bond between DNA strands  H bonds  purine :: pyrimidine  A :: T  2 H bonds  G :: C  3 H bonds

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

10. AP Biology Copying DNA  Replication  2 strands of DNA helix are complementary  have one, can build other  have one, can rebuild the whole

11. AP Biology 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. AP Biology 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. AP Biology Watson and Crick … and others… 1953 | 1962

14. AP Biology Maurice Wilkins… and… 1953 | 1962

15. AP Biology Rosalind Franklin (1920-1958)

16. AP Biology X-ray crystallography X-ray diffraction pattern Photographic film Diffracted X-rays X-ray source X-ray beam Crystal Nucleic acidProtein (a) X-ray diffraction pattern(b) 3D computer model

17. AP Biology 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)

18. AP Biology Another interesting note…  ATP Adenosine triphosphate ++  modified nucleotide  adenine (AMP) + P i + P i

19. AP Biology HELIXHELIX

20. AP Biology 2006-2007 Macromolecule Review

21. AP Biology Carbohydrates  Structure / monomer  monosaccharide  Function  energy  raw materials  energy storage  structural compounds  Examples  glucose, starch, cellulose, glycogen glycosidic bond

22. AP Biology Lipids  Structure / building block  glycerol, fatty acid, cholesterol, H-C chains  Function  energy storage  membranes  hormones  Examples  fat, phospholipids, steroids ester bond (in a fat)

23. AP Biology 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

24. AP Biology Nucleic acids  Structure / monomer  nucleotide  Function  information storage & transfer  Examples  DNA, RNA phosphodiester bond

25. AP Biology 2007-2008 Ghosts of Lectures Past (storage)

26. AP Biology Building the polymer

27. AP Biology RNA & DNA  RNA  single nucleotide chain  DNA  double nucleotide chain  N bases bond in pairs across chains  spiraled in a double helix  double helix 1 st proposed as structure of DNA in 1953 by James Watson & Francis Crick (just celebrated 50th anniversary in 2003!)

28. AP Biology Information polymer  Function  series of bases encodes information  like the letters of a book  stored information is passed from parent to offspring  need to copy accurately  stored information = genes  genetic information