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DNA. CHEM 210 Spring 2014 Dr. Vilchiz. FATHER of GENETICS. Gardner Beekeeper Physicist Friar Failed School Teacher, 1851 & 1856 Researcher. JOHANN “GREGOR” MENDEL. Researcher Work on heredity on Mice Forced to change to plants Inheritance of traits on Pea Plants
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DNA CHEM 210 Spring 2014 Dr. Vilchiz
FATHER of GENETICS • Gardner • Beekeeper • Physicist • Friar • Failed School Teacher, 1851 & 1856 • Researcher
JOHANN “GREGOR” MENDEL • Researcher • Work on heredity on Mice • Forced to change to plants • Inheritance of traits on Pea Plants • Studied 7 different traits • Size • Seed shape • Flower color • Studied 29,000 plants over 7 years. • Law of Segregation • Law of Independent Assortment • Mendel’s Law of Inheritance, 1865
FRIEDRICH MIESCHER • Physician • Biologist • Study White Blood Cells in 1869 • Isolated various phosphate rich compounds • Named them Nuclein, published in 1871 • Now called nucleic acids • Albrecht Kossel • Research on the chemical structure of the Nucleins • Miescher proposes that Nucleins were involved in heredity.
What is DNA? • A co-Polymer “dimer” • Repeating units are known as nucleotides • A, C, G, T • The two helical strands are held together due to the intermolecular forces between the Hydrogens in one nucleotide and the N or O on another. • The shape (folding) of the “molecule” is very sensitive to Temperature changes.
DNA • Phoebus Levene • 1929- Discovers the Presence of Deoxyribose Sugar in DNA • Shows DNA is made up of Nucleotides • Nucleotides are made of deoxyrobose sugar, phosphate and a “base” • Bases G, A, T, C
NUCLEOTIDES • They are the “starting” materials of xNA • They are composed of… • 1-3 phosphate groups • A 5-C sugar (ribose or deoxyribose) • A base • Purines • Adenine (A) • Guanine (G) • Pyrimidines • Cytosine (C) • Thyamine (T) • Uracil (U)
BASES • Guanine- First isolated in 1844 from guano • Adenine- named in 1885 (previously known as Vitamin B4) • Thymine- discovered ~1890 … it is a derivative of Uracil. • Cytosine- Discovered in 1894
DNA • 1943- William Astbury: 1st X-Ray Images of DNA • 1949- Linus Pauling: Proposes the Helical Structure for some proteins • 1950- Erwin Chargaff: Discovers the relationship between A & T and G & C
DNA • 1952- Alfred Hershey & Martha Chase: Show DNA is responsible for the replication of Viruses • 1952- Maurice Wilkins and Rosalind Franklin: take X-rays of DNA x-tals • Franklin Died in 1958…
DNA • 1953- James Watson and Francis Crick:Publish their description of the 3-D structure of DNA • Based on the illegally obtained notes of Franklin • 1962 the Nobel Prize in Medicine awarded to Watson, Crick and Wilkins
GENETIC CODE • 1966-A group of 4 scientists crack the genetic code • 64 nucleotide triplets constitute the genetic code of ALL cells and viruses. • 1972- Paul Berg using the work of Peter Lobban and Dale Kaiser splices DNA… creating the first strand of Recombinant DNA • 1977- Fred Sanger sequences DNA • 1982- Eli Lilly produces the first genetically engineered drug.
HUMAN GENOME • 1986- 1st discussions of needing the sequencing of the Genome. • 1990- 1st succesful gene therapy • 1994- Genetically Engineered Food approved by FDA • 1996- first mammal cloned • 2000- working “draft” of the HG • 2003- HG completed
AMINO ACIDS • First discovered in 1800’s (asparagine) • There are about 500 known Amino Acids • The basic structure is… • An “R” group that has an amine group on one side and a Carboxylic acid group on the other. • Building blocks of Proteins
AMINO ACIDS • Most Proteins are composed from up to 20 different Amino Acids • The AA sequence can be synthesized in the laboratory… the hard part is the “folding”