2. Summary Structure of DNA (sugar-phosphate backbone, base pairs, double helix) RNA Structure (types, how is it different from DNA?) Transcription (RNA polymerase, 5’ cap, splicing, 3’ poly-A tail, export) Translation (Genetic code, reading frame, tRNA, start/stop codon, ribosomes) Protein Folding (pathway, chaperones)

3. First and Foremost: ATP

4. Basic Structure of DNA Backbone Base Pairs Bonding The Double Helix

5. Basic Structure of DNA The Double Helix

6. Basic Structure of DNA Side and Overhead View

7. Basic Structure of DNA The Backbone

8. Basic Structure of DNA The Base Pairs

9. Transcription RNA Structure Backbone Base Pairs 3-D Structure Types RNA Synthesis Initiation Elongation 5’ Cap Splicing 3’ End

10. Major differences between RNA and DNA 1.R, not D = ribose, not deoxyribose 2.Single stranded rather than double stranded 3.Uracil pairs with adenosine instead of thymine

11. Structure of RNA The Backbone

12. Structure of RNA Single Stranded– Can form base pairs

13. Structure of RNA The Base Pairs

14. Types of RNA mRNA “messenger”  codes for protein rRNA “ribosomal”  forms the ribosome, crucial for protein synthesis tRNA “transfer”  connects RNA with correct amino acid during translation snRNA “small nuclear”  splicing siRNA “small interfering”  technique for interfering with native mRNAs

15. Messenger RNA (mRNA) Coding strand of DNA Non-coding strand

16. Transcription Elongation

17. Transcription Initiation TATA box General Transcription Factors RNA Polymerase Phosphorylation  One way of controlling transcription is to change the availability or phosphorylation state of transcription factors

18. Enhancer/repressor genes are several kbp from the genes they control DNA bends frequently, allowing action at a distance

19. Gene Expression 3 ways to control expression before transcription

20. Transcription 5’ capping of new mRNA Why cap mRNA? Some theories…. 1.Stimulates translation: capped mRNA is translated more readily than uncapped 2.Provides protection against degradation by RNases that target loose 5’ ends 3.Transport out of nucleus

21. Transcription Creating the 3’ End Poly-Adenylation Poly-A Polymerase Poly-A binding proteins Ready for export Poly-A purposes: Same as capping

22. Transcription Splicing  Occurs during Elongation

23. After Transcription The Next Stage

24. Translation The Ribosome Transfer RNA Structure Selection and Attachment of Correct Amino Acid Genetic Code and Reading Frames Elongation Termination

25. Translation The Ribosome

26. Translation tRNA Structure

27. Translation Selection of Correct AA for tRNA

28. Translation Genetic Code: how the cell interprets triplets of bases Some point mutations are more dangerous than others!

29. Translation Start Codon

30. Translation Elongation

31. Translation Termination

32. Translation Reading Frames

33. Protein Structure Overview Chaperones

34. Protein structure: chains of amino acids

35. Protein structure: folding Primary: amino acid sequence Secondary: beta sheet or alpha helix (both can exist in different stretches of one protein) Tertiary: folded upon itself Quaternary: coassembly of several aa chains into a globular protein (optional)

36. Protein Folding Chaperones

37. Summary Structure of DNA (sugar-phosphate backbone, base pairs, double helix) RNA Structure (types, how is it different from DNA?) Transcription (RNA polymerase, 5’ cap, splicing, 3’ poly-A tail, export) Translation (Genetic code, reading frame, tRNA, start/stop codon, ribosomes) Protein Folding (pathway, chaperones)