1 / 27

Understanding Genetic Control and DNA Manipulation

Explore gene control mechanisms, DNA manipulation techniques such as PCR and gel electrophoresis. Learn about the Human Genome Project, genetic engineering applications in bacteria, plants, and animals.

yadid
Download Presentation

Understanding Genetic Control and DNA Manipulation

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. Chapters 15 & 16 Control & Manipulation of Genes

  2. Gene controls • Before Transcription • Access • Acetylation loosens grip of histone, allowing access of polymerase to DNA • Methylation of an allele blocks that gene’s affect • How transcribed • Gene sequences rearranged or multiplied, generate large amounts of gene product

  3. Gene controls • Transcription Processing • mRNA cannot pass out of nucleus without transport protein • Some proteins can block translation from starting • Translation Control • Affect ribosome components (no rRNA, no translation) • Control speed of breaking down mRNA (how many times it can be reused)

  4. Gene controls • X Chromosome Inactivation • Females XX • One X chromosome is 75% “shut down” • Barr body—condensed X chromosome • Random

  5. GENE CONTROLS—PROKARYOTES • Operon—arrangement of promoter and operators that control access to a gene • Lacoperonin E. coli cells • E. coli normally doesn’t use lactose (milk sugar) • Lacoperon binds to gene that would allow use of lactose, prevents it’s transcription • When glucose is scarce but lactose present, activator is synthesized • Activator then prevents lacoperon from functioning, allowing lactose to be used • Inhibition can be reversed

  6. Manipulating dna • Recombinant DNA—any DNA molecule consisting of base sequences from two or more organisms of the same or different species. • Able to combine genetic sequence of different species • Restriction enzymes • Plasmids & cloning vectors

  7. Restriction enzymes • A restriction enzyme is added to a solution with DNA • Enzyme “cuts” DNA at a specific place • Can fuse with DNA molecule “cut” with same enzyme

  8. Restriction Enzymes

  9. Plasmids • Bacteria have two forms of DNA • One chromosome, a single circular DNA strand • Plasmids—small circles of “extra” DNA with only a few genes • Bacteria divide rapidly, providing many new organisms in a short period of time.

  10. plasmids • In nature, bacteria can share characteristics through plasmids • Antibiotic resistance

  11. plasmids • With restriction enzymes, can splice DNA into plasmid • Plasmid taken into bacteria cells

  12. plasmids • “Donor” gene is used by bacteria, produces product of gene • Is now part of bacteria’s genetic code, is passed on during division

  13. plasmids • Uses • Laboratory studies of specific genes • Produce products quickly & cheaply • Insluin • Antibiotics • Vaccines • Animal diseases • HIV • Ebola

  14. pcr • Polymerase Chain Reaction (PCR)—method to reproduce fragments of DNA millions or billions of time • Primer—short stretch of synthetic, single-stranded DNA

  15. pcr • Primers are added to solution with DNA fragments and polymerase • Solution is heated, denaturing and “opening” DNA • Solution is cooled • Primers attach to matching base pairs during cooling • Polymerase starts at primer, synthesizes DNA chain • Process is repeated

  16. PCR • Each “cycle” results in exponential growth • Quickly grow a segment of DNA

  17. pcr • Uses • Forensics • Diagnostics (viral & bacterial diseases) • Paternity or relationship testing • Historical analysis • Mummies, mammoths, etc.

  18. Gel Electrophoresis • DNA is mixed with certain compounds in a solution • The solution is placed into a gelatinous substance • Electrical charge is carried along the gel • The DNA separates along the gel in a pattern based on the structure and weight of the individual genes

  19. Dna fingerprinting • Everyone’s DNA is unique to them • Base-pair patterns different between people • PCR & electrophoresis to find & analyze DNA • 1 in 3,000,000,000,000 chance of unrelated people having identical DNA

  20. Human genome project • 1988—National Institutes of Health combined previously begun research into one project • 2003—Human genome officially completed • Almost 20,000 confirmed genes • Over 2,000 possible genes • Don’t know what all of these genes do! • Much of human genome DOESN’T code for proteins • Many might regulate expression of other genes…. “Master Control” genes

  21. Human genome project • Study diseases & disorders • Be able to predict and detect disease • Gene therapy—transfer one or more normal or modified genes into a person’s body cells • Correct genetic defect • Boost resistance to disease • Imperfect at this time

  22. Genetic engineering • Bacteria • Insulin • Blood-clotting factors • Hemoglobin • Vaccines • Environmental clean-up • Oil spills • Pollutants • Radioactive waste

  23. Genetic engineering • Plants • Drought resistance • Disease resistance • Herbicide resistance • Soil tolerance • Greater yield • Better nutrition

  24. Genetic engineering • Animals • Medical research • Mice susceptible to human diseases • Disease resistance • Environmental resistance • Featherless chickens • Medical proteins • Cattle—human collagen (cartilage, bone, skin repair) • Better nutrition • Low-fat pigs

More Related