2. Nucleic Acids Information storage

3. 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

4. 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

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

6. 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!

7. 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) Purine = AG Pure silver!

8. 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 Dangling bases? Why is this important?

9. 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?

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

11. 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?

12. 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

13. 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)

14. Watson and Crick … and… 1953 | 1962

15. Maurice Wilkins… and… 1953 | 1962

16. Rosalind Franklin (1920-1958)

17. 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

18. 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)

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

20. Review Questions

21. 1.What substance varies within a nucleotide of DNA? A.Deoxyribose B.Nitrogenous Base C.Phosphate Group D.Ribose E.Sugar

22. 2.All of the following bonds are correct EXCEPT: I.A Ξ T II.C Ξ G III.A Ξ U A.I only B.II only C.III only D.I and II only E.I and III only

23. 3.A sample of double-stranded DNA has equal numbers of A. Adenine nucleotides and guanine nucleotides. B. Adenine nucleotides and cytosine nucleotides. C. Cytosine nucleotides and Thymine nucleotides. D. Purines and pyrimidines. E. Thymine and Uracil Molecules.

24. Macromolecule Review

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

26. 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)

27. 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

28. Nucleic acids Structure / monomer – nucleotide Function – information storage & transfer Examples – DNA, RNA phosphodiester bond