Genetic Engineering pp. 258-264

Genetic Engineering 1) Inserting a new a gene 2) Altering a gene 3) Deleting or turning off a gene (gene knockout)

Tools Three important tools used for genetic engineering PCR: takes a single copy of the gene of interest and makes (amplifies) up to a million copies for use Restriction enzymes: act like scissors to cut and manipulate DNA Ligase: an enzyme that acts like a welder to seal the cut up DNA

PCR (polymerase chain reaction)

Restriction Enzymes Restriction enzymes are naturally found in bacteria and used to fight virus infections Each enzyme is specific to the DNA sequence it recognizes and cuts The resulting cut has a “sticky” overhang where foreign can be inserted

Ligase Seals the DNA together by covalently bonding the base pairs at the overhang

Applications and Techniques Gene Cloning

A plasmid (ring of DNA found in bacteria) and human DNA (donor gene) are cut with the same restriction enzyme to make a sticky end Donor gene combines with the plasmid (recombinant DNA) and sealed with ligase

https://www.youtube.com/watch?v=nfC689ElUVk

Plasmid (cloning vector) is inserted back into bacterium so that now the bacteria cell makes that specific protein EX. insulin for diabetics or the clotting factor for hemophilia When a bacterial cell divides it makes clones of itself and the new gene

Gene Therapy Altering or adding genes to treat a genetic disorder Expensive and only lasts as long as the cell line Is viable

Stem Cells Stem cells have not yet specialized, so they can become any body cell Can alter or add DNA first Useful for replacing tissue or organs or cells that don’t repair after damage such as nerve cells

Other Biotech – Organism Cloning Creating a genetic copy of an organism Useful for manufacturing tissue and producing more transgenic individuals