DNA Technology

Terms to know: Recombinant DNA –Genes from different sources are combined and transferred into cells. Ex. Fungus resistance gene put into plant DNA. The donor gene is the gene you want to recombine with another sources of DNA. Cloning Vector –Something that moves the recombinant DNA back into the cell –Ex. –Plasmid-Circular piece of bacterial DNA –Virus

Restriction Enzymes Restriction Enzymes are chemicals that cut DNA. To be really useful, enzymes need to cut DNA into sticky ends. Sticky ends are pieces of DNA that are available to “stick” to another piece of DNA.

How do scientists recombine the DNA???? Remove the donor gene from the chromosome using restriction enzymes. Make sure the cut produces sticky ends. Remove the plasmid from bacterium. Cut the plasmid (vector) DNA open using restriction enzymes to produce sticky ends. Insert the donor gene to close the plasmid. They stick together like tape. Insert the recombined DNA back into the host cell.

Transgenic Organisms Living things that contain recombinant DNA (DNA from another organism). After the gene has been put into the new DNA is must be placed in a living cell. These organisms can be used in: –Pharmaceuticals Ex. Bacteria making human insulin –Gene Therapy –Agriculture

DNA Fingerprinting RFLP-Restriction Fragment Length Polymorphism –Everyone has these sections of DNA but the restriction enzymes cut them into different sized pieces. –The way your DNA cuts is specific to you. How do we see the pieces? –Gel Electrophoresis

Gel Electrophoresis Separates DNA according to the size of the pieces (fragments) DNA is put into a gelatin like substance and an electric charge is applied. Since DNA is negatively charged which direction will it move? Large pieces get “stuck” in the gel and smaller pieces can move further. This makes a “fingerprint”.

Uses for Gel Electrophoresis DNA fingerprints can match DNA at a crime scene DNA fingerprints can determine paternity or relatedness Determine the size of DNA fragments. Sequencing DNA

Human Genome Project Project to determine the sequence of the 3 billion bases that make up human DNA. This 13 year project was completed in 2003 with government and private funding. Accomplished using DNA sequencing gels. –DNA from many different donors was sequenced in 150,000 base segments then put together to create the entire genome of an average individual.

Uses of the human genome project? Gene Therapy-process of “fixing” defective genes to prevent genetic diseases. –If you know where a gene is then you can try to fix it! Still in the testing phase for humans. Not yet approved by the FDA for treatments.

PCR Polymerase Chain Reaction Used to make thousands of copies of one tiny piece of DNA. Uses- –Forensics –To isolate (find) a gene

Cloning- Making exact copies of an organism Steps –Take a full set of DNA from one cell of an organism. –Put the DNA into a stem cell (cell that has not differentiated) –Allow cell to develop into an embryo and eventually a full organism.

Human Genome Project

Why is this important? Biotechnology-use of living organisms to benefit society. Genetic Engineering-manipulating genes of organisms to benefit society. Applications? Forensics, Agriculture, Medicine, Pharmaceuticals, Others?….