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. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.
Biotechnology or Genetic Engineering refers to technology used to manipulate DNA • The procedures are often referred to as genetic engineering • All organisms use the same genetic code
Genes from one kind of organism can be transcribed and translated when put into another kind of organism • For example, human and other genes are routinely put into bacteria in order to synthesize products for medical treatment and commercial use (ex. human insulin, human growth hormone and vaccines are produced by bacteria)
Recombinant DNArefers to DNA from two different source • Individuals that receive genes from other species are transgenic
Vectors • Vectors are used to transfer genes into a host cell • Plasmids & viruses are the most commonly used vectors
Plasmids: • Small rings of DNA in bacterial cells • Used to transfer genes to other organisms • Host bacterium takes up the plasmid, which includes the foreign gene • When bacteria reproduce, plasmids with the new gene are also reproduced • This clones (copies) the gene each time the bacteria reproduces • Known as transformation
Viruses: • Can accept larger amounts of DNA than plasmids • Once the virus enters the host cell, it also reproduces the foreign gene it carries • The copied gene is "cloned"
Restriction enzymes: • Restriction enzymes were discovered in bacteria • Hundreds of different restriction enzymes have been isolated • Each restriction enzyme cuts DNA at a specific base sequence • For example, EcoRI always cuts DNA at GAATTC as indicated
Fragments of DNA that has been cut with restriction enzymes have unpaired nucleotides at the ends called sticky ends • If the vector and the gene to be cloned are both cut with the same restriction enzyme, they will both have complimentary sticky ends • After cutting, the 2 DNA samples are mixed • Fragments with complementary sticky ends join together forming recombinant DNA (contains gene from vector & the gene to be cloned) • Enzyme DNA ligase seals the fragments together
Polymerase Chain Reaction (PCR): • Used to make many copies of small pieces of DNA • Allows large amounts of DNA to be made from a small starting sample • Often used with crime scenes when only a small amount of DNA has been gathered
Cloning: • Clone- a member of a group of genetically identical cells • May be produced by asexual reproduction (mitosis) • A body cell from one organism and an egg cell from another are fused • The resulting cell divides like a normal embryo
It has been used for many years to produce plants (even growing a plant from a cutting is a type of cloning). Animal cloning has been the subject of scientific experiments for years, but garnered little attention until the birth of the first cloned mammal in 1997, a sheep named Dolly.
Human Genome Project • Started in 1990 and completed in 2003 • Research effort by scientists all over the world to sequence all of our DNA (46 chromosomes – over 3.3 billion nucleotides) • Mapping every gene location (loci)
Only 2% of human genome codes for proteins while the other 98% is non-coding which means only about 20,000 to 25,000 genes (expected 100,000) present • About 8 million single nucleotide polymorphisms (SNP) – places where humans differ by a single nucleotide
Benefits include • Improvements in medical prevention of disease, gene therapies, diagnosis techniques … • Production of useful protein products for use in medicine, agriculture, bioremediation and pharmaceutical industries