12 Biotechnology

Biotechnology

the application of science & engineering in the direct or indirect use of living organisms (or their parts or products) in their natural or modified forms

Recombinant DNA technology (rDNA)

The combination of DNA molecules from different biological sources into a new DNA molecule

Plasmids

Extra-chromosomal piece of self-replicating DNA in bacteria

Extra-chromosomal DNA

DNA off chromosomes, either inside or outside the cell nucleus

Restriction Enzymes or Endonucleases Source

found primarily in bacteria that use them to cut the DNA of invading bacteriophages (viruses) into small fragments

Restriction Enzymes Purpose

Excise a piece of DNA from a chromosome using a restriction enzyme in order to transfer it

DNA Ligase

Enzyme that forms phosphodiester bonds between blunt or staggered free ends of DNA to create rDNA

Cloning

Process of producing genetically identical copies of biological entities: (1) DNA fragments (molecular cloning) (2) Cells (cell cloning) (3) Whole organisms

4 Steps of Cloning a DNA fragment

Fragmentation, Ligation, Transformation, Screening

Fragmentation

Use the same restriction enzyme to cut and separate pieces of DNA from a sample and a plasmid/vector

Ligation

Attach the 2 fragments of DNA by base pairing, then use DNA ligase to form bonds to create the rDNA

Transformation

Insert the newly formed rDNA into cells

Screening

Select cells successfully transformed with the recombinant DNA

Polymerase Chain Reaction (PCR)

rapid and versatile method for amplifying target DNA sequences; “molecular photocopying”

Denaturation (PCR)

Heating to 94-96°C so DNA separates into 2 single-strands of DNA

Annealing (PCR)

Cooling to 50-70°C to allow primers (short nucleotide sequences) to bind (or anneal) to complementary bases at opposite ends of the target sequence

Elongation (PCR)

Heating to 70-75°C to allow Taq polymerase (an enzyme) to synthesize 2 new complementary strands of DNA (using the original strands as templates)

Transgenic Animals

to introduce, remove, or modify a gene for a specific trait

Gene Pharming

transgenic livestock produce biologically active pharmaceuticals for human medicine

Biomedical Applications

Animal Engineered as Sources of Transplant Cells, Tissues, and Organs

Xenotransplantation

Transfer of an organ or a tissue from an animal to a human

Genetic Testing

Genetic tests involve direct examination of DNA molecules from blood or other tissue to diagnose a genetic disorder

Gene Therapy

a normal gene is inserted into the genome to replace an abnormal, disease-causing gene

Pharmacogenomics

Study of how an individual’s inherited variation in different genes affects drug response

FDA

Protect public health by assuring the safety, efficacy and security of human and veterinary drugs, biological products, medical devices, our nation’s food supply, food additives, cosmetics, and products that emit radiation

EPA

Protect Americans from significant risks to human health and the environment

APHIS

regulate genetically modified organisms