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Join us on April 25th as we celebrate the completion of the Human Genome Project and the discovery of the double helix structure of DNA. Explore the history of DNA discovery and learn about the scientists who paved the way. Watch informative videos and engage in educational activities. Don't miss out on this exciting event!
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FINDING DNA The Race is on…
APRIL 25 The day commemorates the completion of the Human Genome Project (complete mapping of genes of humans) in April 2003, and the discovery of DNA's double helix.
Finding the A T C G order of an average human and what it codes for
Was the genetic material protein or DNA? • Chapt. 9 Mendel (peas) did not know about DNA. • Worksheet links • Bozeman Biology: DNA and RNA Part I Bozeman Biology: DNA and RNA Part II
The Race to Find DNA Youtubes • Finding the Structure of DNA (9:15) • The Secret of Photo 51(55 minutes) • Watch Friday, April 24 • The story of Rosalind Franklin (2:24) -
Frederick Griffith • A medical officer was trying to find a vaccine against pneumococcus
Rough and Smooth Pneumococcus benign virulent Thick capsule No capsule
Griffith 1920’s • Streptococcus pneumoniae used to show a “transforming factor” • bacteria transformation youtube (23 seconds)
Griffith’s Conclusion • Some material* in the heat-killed S strain of pneumococcus that was responsible for “transforming” the R-strain into a lethal form • transformation= passing the inheritance factor* from one organism to another • *THIS TRANSFORMING FACTOR WAS LATER FOUND TO BE DNA
Oswald Avery 1944 He had reported that DNA, not protein (which was believed at the time), was the hereditary substance (transforming material). Studied medical research
Avery’s Conclusion • EXPERIMENT: Separated the DNA, RNA, protein from S-strain pneumococcus • AVERY PROVED THAT DNA WAS THE TRANSFORMING MATERIAL
Alfred Hershey and Margaret Chase 1953 • Showed that the hereditary material in bacteriophage viruses is DNA. DNA in water
Hershey-Chase Bacteriophages Youtube (1:49) • McGraw-Hill Hershey-Chase Experiment Radioactive P32 in DNA Radioactive S35 in protein
Hershey-Chase • CONCLUSION – • DNA is genetic material because (32P)nucleic acid not (35S)protein guides viral replication
Virus Examples HIV Virus • Cold Virus Bird Flu Virus Ebola Virus
Bacteriophage Structure (Capsid) A D B E C
Virus: Are they Alive? • Viruses can only replicate in a living host. • "Viruses straddle the definition of life. Viruses contain some of the structures and exhibit some of the activities that are common to organic life, but they are missing many of the others.” • Dr. Mark Young of MSU youtube (4:00) • Are virusees alive? (2:57)
Bacteriophage Virus Lytic Infection • 1.Attach to host (E. coli) • 2. Insert DNA • 3. Make DNA parts • 4.assemble DNA parts • 5. Lyse (burst)-kills EXAMPLES: Cold Flu
Lysogenic Infection • 1. Virus lands on host. • 2. Virus injects DNA into host. • 3. Virus DNA attaches to host DNA = prophage. • 4. Virus Prophage will become lytic when conditions are favorable (you are sick, tired). • lysogenic infection youtube (1:25) • Mr. W's "I'm a virus“ (4:02)
PROPHAGE: viral gene inserted and integrated into the circular bacterial DNA chromosome …forever
Lysogenic Cycle Animation • Animation Quiz 2 - Lamda Phage Replication Cycle • EXAMPLES:HERPESHIV • CHICKEN POX
Identifying Bacteria: Shapes • Cocci- spherical • Bacilli – rod • Spirilla – spiral
Identifying bacteria: Groupings • Diplo: Two Staphylo: cluster Sarcina: 8 Tetrad: 4 Strepto:chain
Tests +/- endospore • Gram + and Gram – Sugar Test Aerobic/anaerobic test
What is the structure of DNA? • It is a nucleic acid (macromolecule) • Polynucleotide (polymer) = Made of long chains of Nucleotides(monomers)
Phosphate Group O O=P-O O 5 CH2 O N Nitrogenous base (A, G, C, or T) C1 C4 Sugar (deoxyribose) C3 C2 DNA Nucleotide“monomer of nucleic acid”
MONOMER: NUCLEOTIDE POLYMER: POLYNUCLEOTIDE DNA Structure Macromolecule: Nucleic Acid Ladder sides “rungs”
MADE OF: Sugar Phosphate Base Deoxyribose sugar PO4 4 kinds of bases: (A) (G) (T) (C) (names on next slide) A Nucleotide
4 Types of Base Pairs • A = adenine • T = thymine • C = cytosine • G = guanine • NOW SING THE DNA SONG (next slide)
DNA Song (to the tune of “row, Row, Row Your Boat”) • We love DNA • Made of Nucleotides • Sugar, phosphate, and a base • Bonded down one side • Adenine with thymine make a lovely pair • Cytosine without guanine would feel very bare • Row Your Boat Karaoke
A or G T or C Nitrogenous Bases AG = silver • PURINES -2 rings 1. Adenine (A) 2. Guanine (G) • PYRIMIDINES -1 ring 3. Thymine (T) 4. Cytosine (C) CUT
DNA • Deoxyribonucleic Acid Purine = AG Pyrimidine = CUT
Covalent bonds between a phosphate and two sugar molecules (phosphodiester). • H-bonds between complimentary bases
“Rungs of ladder” Nitrogenous Base (A,T,G or C) “Legs of ladder” Phosphate & Sugar Backbone DNA Double Helix
DNA backbone • Sugar • Phosphate
DNA Structure • Rungs of the Ladder: • Various orders of A, T, C, G • Backbone: • Sugar and phosphates • Alternate
5 O 3 3 O P P 5 5 C O G 1 3 2 4 4 2 1 3 5 O P P T A 3 5 O O 5 P P 3 DNA Double Helix G C
Ribonucleic Acid Three types: mRNA tRNA rRNA What’s RNA?
DNA Double stranded Sugar = deoxyribose Bases: A-T, C-G Found only in nucleus Can repair itself RNA Single stranded Sugar = ribose Bases: A-U, C-G U=uracil Found in and out of the nucleus Cannot repair itself Comparing DNA and RNA“two kinds of nucleic acids”