1 / 45

Chapter 1 2: Molecular Biology of the Gene

Chapter 1 2: Molecular Biology of the Gene. Finding the molecule…..the material must be… Able to store information that pertains to the development, structure and metabolic activities of the cell Stable so that it can be replicated Able to undergo changes ( mutations ).

denzel
Download Presentation

Chapter 1 2: Molecular Biology of the Gene

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Chapter 12: Molecular Biology of the Gene

  2. Finding the molecule…..the material must be… Able to store information that pertains to the development, structure and metabolic activities of the cell Stable so that it can be replicated Able to undergo changes (mutations) 13.1 – THE GENETIC MATERIAL

  3. 1869 – Discovering Nucleic Acids Swiss Physician, Johannes Friedrich Miescher isolated the chemical he called “nuclein” from the nuclei of pus cells Now called nucleic acids DNA (deoxyribonucleic acid) RNA (ribonucleic acid)

  4. NUCLEOTIDES (found in nuclein) Contain a sugar, phosphate and a nitrogen base Adenine Guanine Cytosine Thymine

  5. TRANSFORMATION OF BACTERIA Frederick Griffith attempted to find a vaccine against pneumococcus He found that one type of bacteria could turn into another

  6. DNA WAS DETERMINED TO BE THE TRANSFORMING SUBSTANCE Conclusions: DNA from S strain bacteria causes R strain to be transformed Enzymes that degrade proteins will not stop the transformation Enzymes that degrade DNA does stop the transformation Transformation Animation Activity

  7. Alfred Hershey and Martha Chase Experiments • Experimented with radioactive sulfur (protein) and phosphorous (DNA) • Used to determine whether DNA was the genetic material. • Conclusion:  The radioactive tag on the protein did not go into the bacteria Animation of the Hershey and Chase Experiment

  8. Examine the data below. Do you notice a pattern?

  9. So did Erwin Chargaff... -noticed that all a species had similar ratios of A, T, G, C Chargaff’s Rule Amount of A, T, G, C varies by species, but A = T G = C

  10. ROSALIND FRANKLIN & WILKENS Took pictures of DNA using X-RAY DIFFRACTION

  11. DNA

  12. WATSON & CRICK

  13. Figure 13.6d

  14. DNA: THE DOUBLE HELIX Steps of ladder are bases (A, T, G, C) Sides of ladder are sugar & phosphate Both sides held together by hydrogen bonds

  15. 5’ and 3’ ENDS Each side is antiparallel, the numbers represent the carbons attached in a ring to make deoxyribose

  16. Nucleotide = 1 base Deoxyribose (sugar) 1 phosphate

  17. DNA REPLICATION -the process by which DNA makes a copy of itself-occurs during interphase, prior to cell division Replication is called semi-conservative.

  18. 1. DNA helicase , replication fork. 2. DNA polymerase adds nucleotides and binds the sugars and phosphates. ***DNA polymerase travels from the 3' to the 5' end. The DNA is called the template strand.*** 3. One side is the leading strand - it follows the helicase as it unwinds.

  19. 5. The other side is the lagging strand - its moving away from the helicase (in the 5' to 3' direction). OKAZAKI FRAGMENTS are bound by DNA LIGASE Problem: it reaches the replication fork, but the helicase is moving in the opposite direction. It stops, and another polymerase binds farther down the chain. 6. Multiple replication forks all down the strand.

  20. Figure 13Ac

  21. Animations and Videos of DNA REPLICATION How Nucleotides are Added in DNA Replication (mcgraw-hill) DNA Replication Tutorial at wiley.com DNA Replication at stolaf.edu

  22. GENES SPECIFY ENZYMES

  23. The Central Dogma DNA  RNA Amino Acid (Protein)

  24. Figure 14.3 RNA is a lot like DNA, except: 1. Ribose 2. Uracil 3. Single Strand *Can leave the nucleus, carries the "message" 

  25. Figure 14.6 TRANSCRIPTION: The process where mRNA is made from DNA Follows base-pair rule has uracil instead of thymine RNA polymerase is used to build the strand of RNA

  26. Transcription Animations Transcription: Stolaf.edu Transcription: Concord.org

  27. Figure 14.5 Every 3 bases on mRNA  (messenger RNA) is called a CODON Each CODON specifies one AMINO ACID Chains of amino acids are proteins          (ex.  hemoglobin)

  28. The Central Dogma DNA  RNA Amino Acid (Protein)

  29. Translation:  process by which protein is built from the mRNA  tRNA is used to build an amino acid chain Each 3 bases on mRNA codes for a single amino acid. 

  30. 3 bases on mRNA       = a codon Matching 3 bases on tRNA     = anticodon tRNA has a single attached amino acid

  31. Translation occurs on the ribosome mRNA is threaded through the small and large subunit

  32. Figure 14.10b

  33. Each tRNA delivers an amino acid which binds to the previous amino acid, eventually forming a long chain .....a PROTEIN

  34. All genes start with AUG, also called the START CODON It attaches to anticodon UAC and the amino acid methionine

  35. Figure 14.12

  36. Figure 14.13

  37. Animations of Translation Translation: Stolaf.edu Translation: Concord.org

  38. Figure 14.4

  39. The Big Picture  (aka The Central Dogma)

  40. The Central Dogma From DNA to Protein Protein Synthesis

More Related