Nucleic Acids and Protein Synthesis

1. Nucleic Acids and Protein Synthesis Modern Biology Chapter 10

2. DNA Structure

3. 10-1

4. DNA full name is DeoxyriboNucleicAcid

5. A Nucleotide The monomer of nucleic acids…

6. Structure of DNA • Basic Structure • three basic components • deoxyribose: 5 C sugar

7. Structure of DNA • Basic Structure • three basic components • phosphate group (PO4)3-

8. Structure of DNA Basic Structure three basic components nitrogenous base adenine (A) guanine (G) thymine (T) cytosine (C)

9. Structure of DNA • The double helix • many scientists worked to solve the structure of DNA

10. Chargaff • Concluded that A must bond with T and C with G

12. Structure of DNA • The double helix • many scientists worked to solve the structure of DNA • Rosalind Franklin • took X-ray photographs of DNA • died in 1958 without recognition for her enormous contribution

13. X-ray crystallography

14. Rosiland Franklin

15. Structure of DNA • The double helix • many scientists worked to solve the structure of DNA • Wilkins • received Nobel prize with Watson and Crick

16. Structure of DNA • The double helix • many scientists worked to solve the structure of DNA • Watson and Crick • first to construct a model of DNA molecule • received Nobel prize for their work in 1962 • Primarily piggy-backed on others’ work, but were the first to put the pieces together correctly

17. Watson and Crick

18. Structure of DNA The double helix • two nucleotide chains that wrap around each other • base-pairs form the rungs of the ladder

19. Structure of DNA • The double helix • alternating chains of phosphate groups and deoxyribose molecules form the backbone of the structure • all rungs are of equal length • approx. 10 base pairs per turn of DNA molecule

20. Structure of DNA • Complementary base pairing • to ensure that the rungs are of equal length nucleic acids pair up • base-pairing rules • cytosine bonds with guanine (C-G) • adenine bonds with thymine (A-T)

21. Structure of DNA connected by hydrogen bonds • C and G share 3 H-bonds • A and T share 2 H-bonds

22. Replication

23. Replication of DNA • replication: process of copying DNA • the steps: • double chains must separate between the nucleic acids • replication fork: point at which the chains separate • helicase: enzyme that breaks apart DNA molecule • nucleotide bases match up with their compliments • DNA polymerase: enzyme that assembles new bases to original strand

24. Replication of DNA • replication: process of copying DNA • complimentary bases allow for accurate replication • new strands of DNA actually contain one old strand and one new strand

26. Types of replication possible with a double strand

27. DNA is semi-conservative

28. A movie for your viewing enjoyment Animation Illustrating DNA Replication by Complementary Base Pairing • More complex view

29. Replication of DNA • Accuracy and Repair • highly accurate with only 1 error per 10,000 pairs • mutation: change in a nucleotide sequence

30. Mutation

31. Replication of DNA • Accuracy and Repair • proofreading and repair reduce error rate to 1 error per 1,000,000,000 base pairings • enzymes proofread and repair any errors that are identified • Equivalent to 1,488,095 copies of Huckleberry Finn

32. Fixing the errors

33. Replication of DNA • Accuracy and Repair • some factors increase the rate at which DNA mutates • radiation • certain chemicals • sun light

34. Radiation Excited electrons run around uncontrollably and cause problems. We use this trait for helping patients battle cancer- chemo therapy.

35. Solar Radiation

36. RNA Modern Biology Chapter 10

37. Structure of RNA • full name is RiboNucleic Acid

38. Structure of RNA basic structure • backbone of phosphate groups and ribose • single stranded • uracil (U) replaces thymine in pairing with adenine

39. Types of RNA

40. Types of RNA • mRNA: messenger RNA • carries copy of DNA strand from nucleus to ribosome • single, uncoiled chain

41. Types of RNA • tRNA: transfer RNA • carries specific amino acids to ribosomes to pair with mRNA • single chain (about 80 base pairs long) folded into a hairpin like shape

42. Types of RNA rRNA: ribosomal RNA • Along with proteins rRNA forms ribosomes • globular form

43. Transcription • process where genetic information is copied from DNA to RNA • ANIMATION OF THE PROCESS OF TRANSCRIPTION

44. Transcription • steps of transcription • RNA polymerase binds to DNA in specific sites called promoter regions • DNA unzips and nucleic bases follow complementary base-pairing rules • Termination sequence marks end of transcription • products of transcription are all forms of RNA • Movie Time

45. DNA unzips • RNA polymerase does it’s thing • RNA is formed

46. Comparing DNA and RNA

47. Messenger RNA Ribosomal RNA Transfer RNA Bringamino acids toribosome Carryinstructions Combine with proteins tRNA mRNA rRNA DNA Ribosome Ribosomes RNA Concept Map Section 12-3 RNA can be also called which functions to also called which functions to also called which functions to from to to make up

48. Protein Synthesis

49. Protein structure and composition • proteins are polymers • made up of long chains of amino acids • 20 different amino acids • proteins fold into specific shapes based on the sequence of amino acids

50. The amino acids