1 / 53

DNA: The Molecule of Life

DNA: The Molecule of Life. Alan D. Morales Biology. Introduction. Genetic code : the program of the cell that is passed from one generation to another; tells cells what to do and how to do it Must be able to: 1. duplicate itself quickly and accurately 2. be decoded and put into effect .

anisa
Télécharger la présentation

DNA: The Molecule of Life

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. DNA: The Molecule of Life Alan D. Morales Biology

  2. Introduction • Genetic code: the program of the cell that is passed from one generation to another; tells cells what to do and how to do it • Must be able to: • 1. duplicate itself quickly and accurately • 2. be decoded and put into effect

  3. Discovery of DNA • Griffith: 1928--discovered transformation of bacteria • Avery: 1944-discovered that DNA was the transforming factor • Hershey and Chase: 1952-studied whether viruses that infect bacteria inject protein or DNA • PA Levine- Discovered the nitrogenous bases, deoxyribose, and phosphate group. • Franklin and Wilkins: DNA has a helical structure

  4. What is DNA? • Deoxyribose Nucleic Acid • Chargraff • A=T, G=C • James Watson and Francis Crick • Model of DNA • Double stranded structure • Bases inside

  5. DNA-Deoxyribose Nucleic Acid

  6. What is DNA Made of? • 5-carbon sugar (Deoxyribose) • Phosphate • Nitrogenous Base • Adenine (A) • Guanine (G) • Thymine (T) • Cytosine (C)

  7. What are the Structures of the bases? • Purines • Adenine • Guanine

  8. What are the structures of the bases? • Pyrimidines • Thymine • Cytosine

  9. A View of base pairing • A:T • 2 hydrogen bonds

  10. A View of Base Pairing • G:C • 3 hydrogen bonds

  11. What is important about base pairs? • Can predict sequence of one strand based on the sequence of the other. • Replication and Transcription • Repair of damaged DNA

  12. Linking it all together: A, G, C or T Forms sugar Phosphate Backbone What makes DNA Different from RNA?

  13. Where is DNA in the cell? • Prokaryotic cell: Cytoplasm • Eukaryotic cell: in the chromosomes

  14. DNA-Chromosome Formation • http://www.cleanvideosearch.com/media/action/yt/watch?videoId=4PKjF7OumYo

  15. DNA Replication: • Why? • When cells divides, each new cell needs it’s own copy of DNA. • Where? • Nucleus in Eukaryotes. • Cytosol in Prokaryotes • When? • S phase of Interphase • What causes? • DNA Polymerase

  16. DNA Replication

  17. DNA Replication • DNA Helicase cause DNA to unwind and unzip • SSB: Single strand binding protein keeps DNA separated • RNA Primase add a short segment on each end • DNA Polymerase causes addition of new nucleotides • 3’ to 5’ direction • Leading and Lagging strand • Matching on Base pairing

  18. DNA Replication • Okazaki fragment is small segment of lagging strand of DNA formed during replication • DNA Ligase connect the Okazaki fragments

  19. Comparing DNA Replication in Eukaryotes and Prokaryotes cells • Eukaryotes cells unwind in multiple areas • Prokaryotes cells unwind only in area of replication

  20. DNA Replication Lab • DNA Replication Video

  21. RNA Transcription

  22. Transcription • DNA RNA • What is the difference between DNA and RNA? • Sugar: Ribose • Strands: 1 • Instead of thymine • =Uracil • A, U, C, G

  23. Types of RNA • mRNA-messenger RNA • Take message from DNA out of nucleus to ribosomes • tRNA-transfer RNA • Transfer code to protein • rRNA-ribosomal RNA • Assist with making protein

  24. Transcription • Where? • Nucleus in Eukaryotes • Cytosol in Prokaryotes • What? • DNA copied/written by mRNA • When? • When protein is needed

  25. Transcription • How? • RNA polymerase • Base-pairing • A-U and G-C • Only one strand • RNA Synthesis Animation

  26. Transcription

  27. Transcription Lab

  28. Translation • Language of RNA instructions • A, U, G, C • Codon: three consecutive nucleotides that forms a specific single amino acid from mRNA. • 1 codon=3 nucleotides • Anticodon-3 consecutive nucleotides that from tRNA

  29. Codon • tRNA Molecule Example: UCGCACGGU • UCG-CAC-GGU • Serine-Histidine-Glycine • UCG=Serine • CAC=Histidine • GGU=Glycine • Start Codon • AUG • Stop Codon • UAA, UAG, UGA

  30. Amino Acids-Proteins • Amino acids are attached to tRNA • Amino acids joined together into long chains to make proteins • Protein properties are determined by order of amino acid. • 20 different amino acids

  31. The Genetic Code

  32. Translation • What? • mRNA with tRNA & rRNA Protein • Where? • Cytosol • When? • When proteins are needed • Why? • Proteins are vital for cells

  33. Translation • How? • Ribosomal Subunits • mRNA, tRNA, & rRNA • Stages of Translation • Initiation: AUG starts process • Elongation: Amino acids attach to each other • Termination: ends with stop codon • Translation Animation

  34. Quick Lab • What is the difference between DNA and RNA? • Replicate the following DNA Molecule: (hint: in DNA Replication you will match it to another DNA molecule): GACAAGTCCACAATC • Transcribe the following DNA Molecule (hint: in Transcription you will match it to mRNA molecule): GACAAGTCCACAATC

  35. Genetic Code

  36. Quick Lab Answers • What is the difference between DNA and RNA? • Sugar: Ribose • Strands: 1 • Instead of thymine • Replication of DNA Molecule: CTGTTCAGGTGTTAG • Transcribe into mRNA molecule: CUGUUCAGGUGUUAG

  37. Protein Synthesis Review • Replicate the following DNA molecule • DNA: GACTTACCGGGA • DNA: CTGAATGGCCCT • Transcribe the following DNA molecule • DNA: GACTTACCGGGA • mRNA: CUGAAUGGCCCU

  38. Protein Synthesis Review • Translate the following RNA molecule into a protein • mRNA: CUGAAUGGCCCU • tRNA: GACUUACCGGGA • GAC-UUA-CCG-GGA • Aspartic Acid-Leucine-Proline-Glycine

  39. Pop Quiz • Translate following mRNA molecule: GACAAGUCCACAAUC • tRNA strand: • Amino Acid:

  40. Pop Quiz Answers • Translate from mRNA molecule to amino acid sequence via tRNA • tRNA strand: CUG-UUC-AGG-UGU-UAG • Amino Acid: Leucine-Phenylalanine-Arginine-Cysteine-Stop

  41. Genes and Protein • Genes contain information to assembly Protein • Proteins carry out the instructions of the genes • One gene-One enzyme • Beadle-Tatum

  42. Gene Regulation • Ability of an organism to control which genes are transcribed in response to the environment

  43. Gene Regulation • Prokaryote Cells • Operon-Segment of DNA that contains genes for the protein in specific metabolic pathway • Eukaryote Cells • Regulate protein synthesis using various transcription factors, nucleosomes structures and RNA interferences

  44. Why is this important? • Mutations • Genetic Engineering • Gene Splicing • Cloning

  45. Mutations • Mutation-change in the DNA sequence that affect genetic information • Types of Mutations • Point Mutation • Chromosomal Mutation

  46. Mutations • Point Mutation- • one nucleotide has changed

More Related