Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Chapter 12 GENETIC ENGINEERING AND THE MOLECULES OF LIFE 1 Contents 12.1 The Chemistry of Heredity 12.2 The Double Helix of DNA 12.3 Cracking the Chemical Code 12.4 Protein Structure and Activity: Form and Function 12.5 The Human Genome Project 12.6 Genetically Engineered Medical Treatments 12.7 Genetically Engineered Agriculture 12.8 Cloning Mammals and Humans 12.9 The New Prometheus? 2 The Chemistry of Heredity Genetics: Fundamentals Human Genome: - 10 million million (10x1012) cells with a nucleus - each cell has a complete set of genetic instructions to make another you(biologically) - 23 pairs of chromosomes - 100,000 genes - def’n: totality of human hereditary information in molecular form 3 DNA DNA (deoxyribonucleic acid): molecule that carries genetic information in all species - DNA of one cell unraveled = 2 meters long 3 parts to DNA: (i) Phosphate group (ii) Sugar (deoxyribose) (iii) Nitrogen bases 4 DNA Put all 3 groups together, called a nucleotide Adenosine phosphate A DNA molecule consists of thousands of nucleotides put together in a long chain (left) 5 The Double Helix of DNA X-Ray Diffraction of DNA • R. Franklin • J. Watson & F. Crick • 1962 Nobel in Chemsitry 6 DNA Turns out that: Adenine bonds with Thymine Guanine binds with Cytosine Called complementary bases: A=T G=C 7 DNA Double Helix DNA is double stranded and is shaped like a spiral staircase. Ex. What is the complementary strand of DNA for the following sequence: ATAGCCG 8 DNA Replication 9 Cracking the Chemical Code DNA: Blueprint of Life? How does DNA provide genetic information, where does the information come from? Key is in the sequences of nitrogen bases. DNA: blueprint for making proteins Proteins: made up of amino acids consist of/or regulate everything in the chemistry of life 10 DNA to Proteins OK, the instructions are in the sequence of bases. There are 20 amino acids How many bases encode for an amino acid? if it were 1 base = 1 amino acid, then there would only be 4 amino acids found in proteins. There are up to 20 amino acids found in proteins. if it were 2: 42 = 16, not enough 3 bases: 43 = 64 3 bases = codon 11 Codon table 12 DNA to Proteins Transcription: DNA to mRNA Translation: mRNA to protein 13 Protein Structure and Activity: Form and Function Polypeptide Backbone 14 Protein structure • The peptide bond allows for rotation around it and therefore the protein can fold and orient the R groups in favorable positions • Weak non-covalent interactions will hold the protein in its functional shape – these are weak and will take many to hold the shape 15 Secondary structures • 2 regular folding patterns have been identified – formed between the bonds of the peptide backbone • -helix – protein turns like a spiral – fibrous proteins (hair, nails, horns) • -sheet – protein folds back on itself as in a ribbon –globular protein 16 Tertiary structure • The overall fold result in increase in stability • The shape is maintained through H-bond, intermolecular ionic and covalent bond and interactions of amino acid residues with water 17 Protein function – – – – Enzymes, exp : chymotrypsin Structural, exp: collagen, hair Transport : hemoglobin etc – Sickle cell anemia differs from normal blood cell due to replacement of hemoglobin amino acid two glutamic acid by valine – Hemoglobin is a transport protein 18 The Human Genome Project What is the Human Genome Project? • International effort to map all gene in human organism • Started in 1989 lead by J. Watson • Finished June 26, 2000 (co-announced by President Bill Clinton and PM Tony Blair) Definition: GENOME – the whole hereditary information of an organism that is encoded in the DNA. • Aims of the project: – – to identify the approximate 100,000 genes in the human DNA. determine the sequences of the 3 billion bases that make up human DNA. – store this information in databases. develop tools for data analysis. address the ethical, legal, and social issues that arise from genome research. – – 19 Whose genome is being sequenced? - the first reference genome is a composite genome from several different people. generated from 10-20 primary samples taken from numerous anonymous donors across racial and ethnic groups. 20 Benefits of Human Genome Project research • improvements in medicine. • microbial genome research for fuel and environmental cleanup. • DNA forensics. • improved agriculture and livestock. • better understanding of evolution and human migration. • more accurate risk assessment. 21 Genetically Engineered Medical Treatment Recombinant DNA: manipulating gene pools Cut out DNA that encodes for human insulin Splice it into E. Coli plasmid (DNA) Ecoli reads DNA and starts making insulin. Human Growth Hormone (HGH): previously, a 1 year supply required harvesting the pituitary glands from 80 human cadavers • DNA recombinant technology offers many biocatalysis • Greener reaction condition • Atorsvastatin produced from (R)-4-cyano-3hydroxybutyrate which was produced by process using biocatalyst (enzyme) • The enzyme was a product of DNA recombinant 24 Genetically Engineered Agriculture Transgenic plants (organisms) • Artificially created higher plants and animals that share the genes of another species • The focus of development – Improve production stability – Give nutritional benefits to the consumer – Reduce environmental effect of intensive and extensive agriculture – Increase the availability of pharmaceutical and vaccines 25 How to create transgenic plants Agrobacterium tumefaciens Plant cell DNA containing gene for desired trait Ti plasmid T DNA Restriction site Insertion of gene into plasmid using restriction enzyme and DNA ligase Recombinant Ti plasmid Introduction Regeneration into plant of plant cells in culture T DNA carrying new Plant with new trait gene within plant chromosome •Nitrogen fixing corn, corn that capable in fixing N2 •Contain nitrogen fixing bacterial genes •Transgenic soybeans which is resistance to herbicides Mixing Genes: Transgenic Organisms Cloning Mammals and Humans Nuclear transfer/ Somatic cell nuclear transfer (A, B) nucleus is sucked of cell (C) New nucleus is picked up (D) Nucleus/DNA is inserted into the egg 28 Dolly, 1996-2003 29 Snuppy, 2005 Snuppy and his “father” Snuppy and his surrogate mother 30 Human cloning • Many reports said the success of the somatic nuclear transfer • After electrical jolt, the embryo started growing • No report of embryo development to human • The intention of researcher is to harvest stem cell The New Prometheus? • We have clone animals • Next logical step would be creating new organism or cloning human “the super one” • However we could not removed defective gene from the pools • And cloning or creating superman could end up with creating a new promatheus 31 THANK YOU 32