CHP: 13 BIOTECHNOLOGY

GENETIC ENGINEERING  The procedure for cleaving DNA from an organism into smaller fragments & inserting the fragments into another organism of the same or different species

RECOMBINANT DNA  DNA made from connecting fragments of DNA from different sources  Ex: Bacteria, glowing pigs  That organism uses the foreign DNA as its own.

TRANSGENIC ORGANISMS  Organisms that contain functional recombinant DNA Steps to produce transgenic organisms 1. Isolate the foreign DNA to be inserted 2. Join the DNA w/something that can transport it 3. Transfer the recombinant DNA into a host  Used in medicine & agriculture

RESTRICTION ENZYMES  Bacterial proteins that have the ability to cut both strands of the DNA molecule at certain points  DNA can only be used for recombination when it is cut into smaller fragments  STICKY ENDS- result of cutting the DNA into double stranded fragments. The ends can be joined to complementary strands to form recombinant DNA.  They join easily because the ends are sticky

HUMAN GENOME PROJECT  International effort to map & sequence human DNA  The sequence is 3 billion base pairs of DNA  LINKAGE MAP- genetic map that shows the location of genes on a chromosome  CROSSING OVER- occurs during meiosis, the offspring have a combination of alleles not found in either parent. Genes that crossover are closer together than those that rarely do

 Diagnosis of genetic disorders would be easier if the DNA sequence is known  CELL CULTURE- to obtain a sample of DNA, cells are grown in a nutrient medium, cells are all identical (clones)  GENE THERAPY- insertion of normal genes into human cells to correct a genetic disorder. In the trial stage for humans, 1 st trial has been on cystic fibrosis patients (nasal spray)

DNA FINGERPRINTING  Used to convict/acquit individuals in a criminal case. Each person is genetically different  Obtained from blood, skin, hair, semen. They use electrophoresis to separate DNA fragments.

VECTOR TRANSFER DNA  The cleaved fragments of DNA must recombine w/something else  Vector- means by which foreign DNA can be transferred into the host cell.  2 TYPES OF VECTORS 1. Mechanical- micropipette or tiny bullets (metal) coated w/pieces of DNA shot into the cell using a gene gun 2. Biological- viruses & plasmids. Plasmid- small ring of DNA found in bacterial cells

GENE SPLICING  Rejoining cut DNA fragments  Foreign DNA is recombined into a plasmid or viral DNA GENE CLONING  Process of making genetically identical copies of recombinant DNA  Cloning is possible because a foreign piece of DNA has been integrated into that cell’s DNA and is replicated w/the hosts DNA

DNA SEQUENCING  Sequencing is important to understand DNA  GEL ELECTROPHORESIS- a set of DNA strands that vary in lengths are produced.  The strands are placed in a gel w/dye which binds to DNA. Then an electric current is passed through it.  Bands appear in the gel sequence. Small fragments move farther than larger ones

Applications of DNA Technology  Transgenic bacteria in agriculture- removal of a certain gene from a bacterium prevents frost damage to crops.  Industry- engineered to break down pollutants, degrade oil  Medicine- produce molecules to treat human diseases, produce growth hormones, interferon for cancer, human insulin

Transgenic Plants  Difficult to insert DNA into plants because of the cell walls (use gene gun)  Genetically engineered to resist herbicides, produce internal pesticides, increase protein production, produce fruit that ripens later, or grow in unfavorable conditions.

Transgenic Animals  Use genes to produce livestock that is bigger or produces more milk, or milk that contains certain chemicals (protein that dissolves blood clots)

Belgian Blue Cow- can produce gallons of milk at a time