ch 21 Principles and Applications of Modern Biotechnology

Biotechnology

The use of living organisms or their products to develop products or processes that are beneficial to humans.

Recombinant DNA technology

The use of in vitro molecular techniques to isolate and manipulate fragments of DNA.

Gene cloning

The technique of isolating and making many copies of a specific gene.

Vector DNA

A DNA molecule that acts as a carrier for a DNA segment to be cloned and can replicate independently of host chromosomal DNA.

Restriction enzymes (Endonucleases)

Bacterial enzymes that bind to specific DNA sequences and cleave the DNA at defined locations.

Sticky ends

Short, single-stranded regions of DNA generated by restriction enzymes that can base-pair with complementary sequences.

Blunt ends

DNA fragments generated by certain restriction enzymes (like NaeI) that have no single-stranded overhangs.

DNA ligase

The enzyme that catalyzes the covalent linkage of the sugar-phosphate backbones of DNA fragments.

Selectable marker

A gene (such as ampR) in a vector that allows for the identification of host cells that have successfully taken up the DNA.

Competent cells

Cells that have been treated with agents to make them permeable to DNA for the purpose of transformation.

Transformation

The process by which a bacterial cell takes up a plasmid vector from its environment.

Transfection

The process of introducing viral vectors into a host eukaryotic cell.

Blue-white screening

A technique using the lacZ gene and X-Gal to differentiate between colonies with recombinant vectors (white) and recircularized vectors (blue).

Reverse transcriptase

An enzyme used to synthesize DNA from an RNA template.

cDNA (Complementary DNA)

DNA that is synthesized using RNA as a starting template.

DNA library

A collection of recombinant vectors, each containing a different fragment of DNA.

Genomic library

A DNA library constructed using chromosomal DNA as the starting material.

cDNA library

A DNA library constructed using cDNA as the starting material.

Polymerase Chain Reaction (PCR)

A method used to amplify a specific sequence of DNA without the aid of vectors or host cells.

Taq polymerase

A thermostable DNA polymerase from Thermus aquaticus used in PCR to withstand high-temperature heating steps.

PCR Denaturation

The first step of PCR where high temperature is used to separate DNA strands.

PCR Annealing

The second step of PCR where lower temperatures allow primers to bind to the template DNA.

PCR Extension

The third step of PCR where DNA polymerase synthesizes a complementary DNA strand.

RT-PCR (Reverse Transcriptase PCR)

A sensitive method used to detect and quantify specific RNA levels by converting them into cDNA before amplification.

Real-time PCR

A variant of PCR that uses fluorescence to quantitate the amount of DNA or RNA present in a sample during the amplification process.

Dideoxy sequencing

A method developed by Frederick Sanger that uses chain-terminating nucleotides (ddNTPs) to determine DNA sequences.

Site-directed mutagenesis

A technique used to introduce specific, predetermined mutations into a cloned DNA sequence.

CRISPR-Cas technology

A gene-editing system derived from bacteria that uses a single guide RNA (sgRNA) and Cas9 protein to make double-strand breaks in target genes.

Northern blotting

A technique used to identify a specific RNA molecule within a mixture.

Western blotting

A technique used to identify a specific protein within a mixture using primary and secondary antibodies.

EMSA (Electrophoretic Mobility Shift Assay)

A method used to determine if a protein binds to a specific DNA or RNA fragment based on slower mobility in a gel.

DNase I footprinting

A technique that identifies the specific DNA site where a protein binds by protecting that region from enzymatic digestion.

GMO (Genetically Modified Organism)

An organism that has received genetic material via recombinant DNA technology.

Transgenic organism

An organism that has received genetic material from a different species.

Bioremediation

The use of living organisms or their products to decrease pollutants in the environment.

Biotransformation

The modification of a toxic pollutant's structure by a microorganism's enzymes.

Vaccine

A biological preparation that provides active acquired immunity to a particular infectious disease.

Molecular pharming

The production of medically important human proteins in the mammary glands of livestock.

Reproductive cloning

Biotechnology methods that produce two or more genetically identical individuals.

Stem cell

A cell with the capacity to divide and differentiate into one or more specialized cell types.

Totipotent

A stem cell (like a fertilized egg) that can give rise to all cell types in the adult organism.

Pluripotent

A stem cell (like ES or EG cells) that can differentiate into almost any cell type but cannot produce an entire individual.

Multipotent

A stem cell that can differentiate into several related cell types, such as hematopoietic stem cells.

T-DNA vector

A vector derived from the Ti plasmid of Agrobacterium tumefaciens used to introduce cloned genes into plants.

Biolistic gene transfer

A method of producing transgenic plants by bombarding cells with DNA-coated microprojectiles from a "gene gun".