1. DNA RNA & Proteins

2. James Watson & Francis Crick and Their DNA Model

3. Winning the Nobel Prize

4. Watson & Crick on the 50 th anniversary of their discovery

5. Rosalind Franklin’s Famous Photo 51 of DNA

6. Rosalind Franklin’s Lab

7. Erwin Chargaff, Jerry Donahue, Lawrence Bragg

8. DNA Polymer of nucleotides (phosphate group bonded to deoxyribose bonded to a nitrogen base)

9. DNA Nucleotide

10. A Nucleotide

11. 4 Nitrogen Bases of DNA Adenine (A) Thymine (T) Guanine (G) Cytosine (C)

12. Adenine and guanine are purines Cytosine and thymine are pyrimidines

13. Purines

14. Pyrimidines

15. Nucleotides Bond Together in Long Chains The two chains of nucleotides are bonded in the middle by the paired bases

16. Base Pairing Rule Adenine bonds to Thymine Guanine bonds to Cytosine BASES THAT BOND ARE CALLED COMPLEMENTARY BASES

17. Bases Bond by Hydrogen Bonds

18. The 2 DNA Chains are Anti- Parallel

20. DNA Replication Before cell division, cells copy (replicate) their DNA

21. An enzyme breaks the hydrogen bonds holding the paired bases together (unzips the DNA)

22. Complementary nucleotides bond to the separated DNA chains (A to T and G to C) DNA polymerase enzymes bond new DNA nucleotides to the original DNA strands The original strand serves as a template for the new strand

25. DNA Replication

26. At the end of DNA replication, there are two identical DNA molecules Each DNA molecule contains an original strand and a new strand (semi- conservative)

27. Proofreading enzymes check for mistakes during replication (bonding 50 base pairs per second means mistakes will be made!) http://www.youtube.com/watch?v=Bju4C5GxeQs&feature=r elated

28. RNA Ribonucleic acid A polymer of nucleotides The sugar in RNA is ribose (instead of deoxyribose, as in DNA)

29. Comparison of Ribose and Deoxyribose

30. RNA nucleotides do not have thymine, but contain uracil instead

31. RNA is one strand of nucleotides (DNA is two chains of nucleotides) So RNA is a single helix, but DNA is a double helix

33. 3 Types of RNA tRNA (transfer RNA) mRNA (messenger RNA) rRNA (ribosomal RNA) http://www.dnatube.com/video/1017/Co mpare-DNA-and-RNA-in-structural- basis

34. tRNA

35. TRANSCRIPTION (RNA Synthesis) A gene for a specific protein is turned on DNA “unzips” and unwinds (as in replication) Complementary RNA nucleotides bond to one strand of DNA (function of RNA polymerase)

36. Bases must be complementary C on DNA bonds to G on RNA G on DNA bonds to C on RNA T on DNA bonds to A on RNA A on DNA bonds to U on RNA

37. RNA breaks away from the DNA template DNA strands reform the hydrogen bonds RNA can then exit the nucleus via pores in the nuclear membrane

38. Transcription

41. http://www.youtube.com/watch?v=vJSmZ3D sntU&feature=related

42. Translation – the making of a protein Begins when mRNA attaches to a ribosome The genetic code of mRNA is read three bases at a time (codons)

43. Each codon specifies a particular amino acid that will be placed in the chain to build the protein molecule

44. The tRNA with its specific amino acid pairs to the codon of the mRNA When a second tRNA with its specific acid pairs to the next codon, the attached amino acid breaks from the first tRNA and attaches to the amino acid of the 2 nd tRNA The ribosome forms a peptide bond between the amino acids

45. The empty tRNA moves off and picks up another matching amino acid from the cytoplasm in the cell This sequence is repeated until the ribosome reaches a stop codon on the mRNA, which signs the end of protein synthesis

46. Beginning of Translation

47. Translation

48. Termination of Translation

49. http://www.youtube.com/watch?v=NJxobgkP EAo

53. The Central Dogma of Biochemistry

55. http://www.dnatube.com/video/1027/Central- Dogmahttp://www.dnatube.com/video/1027/Central- Dogma