EQ: What is the Secret of Life? EQ: How can one organism pass its traits to the next generation? EQ: How can new traits arise?

Transcription

1 EQ: What is the Secret of Life? EQ: How can one organism pass its traits to the next generation? EQ: How can new traits arise?

2 Intro to DNA Miller Ch. 12

3 I. Search for the Secret Morgan fruit flies Griffith chromosomes mice, bacteria transformation later, Avery: it was DNA Hershey, Chase bacteria, virus DNA Wilkins, Franklin X-rays helix Watson, Crick final model

4 The Structure of DNA

5 The Structure of DNA

6 Structure of DNA

7 Mini Quiz 1: DNA Your Names Per Date Match the scientists below with the conclusions drawn from their work (not all of the names will be used) Hershey & Chase Franklin Pauling Brenner Griffith Chargaff Watson & Crick Avery 1. Dead bacteria transformed harmless bacteria into lethal bacteria. 2. Discovered that it is DNA that stores and transmits heredity 3. The genetic material in bacteriophages is DNA, not protein 4. Used X-rays to figure out that DNA is a helix, or spiral. 5. Discovered the complete model for DNA structure 6. List the first letters of the four kinds of bases that store your genetic code in DNA:

8 Quizzie: scientists work 1. Hershey & Chase 2. Chargaff 3. Wilkins, Franklin 4. Crick & Watson 5. Griffith, Avery A. %A=%T, %G=%C B. viruses use DNA to pass on traits C.x-rays show DNA is a helix D. finalized current model of DNA structure E. bacteria probably use DNA to pass on traits

9 DNA replication base pair bonding each side is template helicase unzips polymerase plays matchmaker leading & lagging strands

10 Story Time excerpt from Genome, by Matt Ridley

11 II. RNA & Protein Synthesis A. AERT 1. triplet code B. RNA 1. structure 2. types a. mrna, rrna, trna 3. Transcription...

12 Section 12-3 Transcription Adenine (DNA and RNA) Cystosine (DNA and RNA) Guanine(DNA and RNA) Thymine (DNA only) Uracil (RNA only) RNA polymerase RNA DNA

13 II. RNA & Protein Synthesis A. The Genetic Code 1. mrna triplets a. UUU= phe b. AGU= ser ex: AUGCGCCAGUGA = met - arg - glu

14 Translation Nucleus Phenylalanine trna Lysine mrna Methionine Ribosome mrna Start codon

15 Translation (continued) The Polypeptide Assembly Line The ribosome joins the two amino acids methionine and phenylalanine and breaks the bond between methionine and its trna. The trna floats away, allowing the ribosome to bind to another trna. The ribosome moves along the mrna, binding new trna molecules and amino acids. trna Growing polypeptide chain Ribosome Lysine trna mrna mrna Ribosome Translation direction Completing the Polypeptide The process continues until the ribosome reaches one of the three stop codons. The result is a growing polypeptide chain. Go to Section:

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19 Translate this (write the first three letters of the a.a. s) 1.AUG,GAG,GAA,AUA,GAU,UGA 2.AUG,GUG,GAA,AUA,GAU,UGA 3.AUG,GGG,AAA,UAG,AUU,GA 4.AUG,GCA,GGA,AAU,AGA,UUG,A

20 Genetic Engineering - Chapter 13

21 Vocab restriction enzymes palindromic nucleotide sequences

22 Gel Electrophoresis

23 Gel Electrophoresis [class demo of how this works] Sorts DNA fragments by size compare two different DNA molecules (how?) diff mols will have diff restriction sites thus frags of diff lengths

24 Gel Electrophoresis Normal!-globin allele 175 bp 201 bp Large fragment Ddel Ddel Ddel Ddel Sickle-cell mutant!-globin allele 376 bp Large fragment Normal allele Sickle-cell allele Ddel Ddel Ddel Ddel restriction sites in normal and sickle-cell alleles of!-globin gene Large fragment How many fragments? What sizes? 201 bp 175 bp 376 bp Electrophoresis of restriction fragments from normal and sickle-cell alleles

25 Sequencing DNA Use Gel Electrophoresis to figure out the order of the bases Human Genome Project Benefits of knowing your DNA? compare genes/organisms understand gene function change genes

26 Restriction Fragment Length Polymorphisms RFLP aka riff-lips variation in non-coding regions diff restriction sites diff fragment lengths = genetic markers: DNA fingerprints aka DNA Profiling

27 DNA Fingerprinting Paternity which kids are from Mom and Dad? Crime Which suspect committed the assault?

28 GMO s & Cloning

29 Genetically Modified Organism = GMO How are they made? recombinant DNA tech used to......put cloned gene into GMO s genome = Pharm animals, plants some GMO s are transgenic = contain DNA from other species e.g. golden rice (vitamin A) golden rice How do we use them? vaccines, medicines transgenic microorganisms insulin, HGH, clotting factor breeding shortcuts milk production in cows musculature in beef shelf life & pesticide resistance in plants e.g. Monsanto s Triple Stack Corn (tm)- resists Roundup & two corn pests Pro: Con:

30 GMO Controversy Some believe that genetic modification and engineering: Constricts farmer seed and variety privileges. Technology Protection - 2nd gen makes sterile seeds Confers private ownership of otherwise commonly held life forms. Creates unanticipated environmental effects. Threatens human health. Suppresses the development and integrity of less intensive, more sustainable farming systems. Damages local farming economies. Others believe that genetic modification and engineering: allows for higher crop yield economy, pop. size, health improves health of poor not enough money to afford diverse diet uses less land for food (more for people) means not as much pesticide/insecticide needed

31 Cloning genetically identical organisms/cells derived from single parent How are clones made? extracted donor cells made dormant nuc removed from egg cell donor fused to egg (elec) developed like zygote implanted into surrogate mom totipotency inversely related to age of donor = able to become any cell Cloning Pro: Cloning Con: Therapeutic cloning? (eg stem cells) embryonic vs adult stem cells totipotent vs pluripotent 11/07: pluripotent cells from human adult skin cells(!)(?) 3/09: ban on embryonic stem cell lines lifted Reproductive human cloning?