Chapter 14: Biotechnology & Recombinant DNA

Vocabulary study set covering biotechnology, polymerase chain reaction (PCR), DNA fingerprinting, recombinant DNA technology, and gene therapy.

Polymerase Chain Reaction (PCR)

A technique that acts as "DNA replication in a test tube" to amplify a specific target DNA sequence, producing millions of identical copies from a minuscule starting sample.

Taq DNA Polymerase

A heat-tolerant enzyme required in PCR that extends primers to synthesize new DNA strands at an optimal temperature of $72^\circ\text{C}$.

Denaturation (PCR)

The first thermal step of a PCR cycle where high temperature separates double-stranded DNA into single strands.

Annealing (PCR)

The second thermal step of a PCR cycle where lower temperature allows primers to bind to complementary target sequences.

Extension (PCR)

The third thermal step of a PCR cycle occurring at $72^\circ\text{C}$, during which Taq DNA polymerase extends the primers to synthesize new complementary strands.

DNA Fingerprinting

A method that uses PCR to amplify short tandem repeats (STRs) or non-coding regions of DNA and separates them by size (e.g., gel electrophoresis) to generate a unique banding pattern.

Short Tandem Repeats (STRs)

Non-coding regions of DNA amplified during DNA fingerprinting that yield a repeat pattern unique to each individual, with the exception of identical twins.

Restriction Enzymes

Molecular "scissors" that recognize specific short palindromic DNA sequences and cut both strands, producing complementary single-stranded sticky ends.

Sticky Ends

Complementary single-stranded ends produced when restriction enzymes cut palindromic double-stranded DNA sequences.

DNA Ligase

Molecular "glue" that covalently seals the sugar-phosphate backbone, joining a target gene into a vector plasmid.

Recombinant DNA

DNA from two or more difference sources. It requires a vector that carries the rDNA, restriction enzymes to cut DNA at specific sequences, and DNA ligase to glue the ends together.

Plasmid

A bacterial vector carrier that is cut with restriction enzymes and ligated with a target gene to produce recombinant DNA.

Transformation

The step in producing a recombinant DNA molecule in which the recombined plasmid is introduced into host bacterial cells.

Bioremediation

An application of genetically modified bacteria used to clean up environmental pollutants such as oil spills and toxic waste.

How to produce human insulin from genetically modified bacteria

1. Use the restriction enzyme to cut the insulin gene from a human cell

2. Use the same restriction enzyme to cut the plasmid

3. Insert the insulin gene into the plasmid (rDNA)

4. Put the plasmid back into bacteria

5. Bacteria use the DNA to produce human insulin!

Gene Therapy

Procedures that introduce normal genes into a patient to correct faulty genes or treat disease.

Ex Vivo Gene Therapy

Gene therapy carried out outside the body, in which cells are removed from a patient, given a functional gene via a vector, and returned to the patient. (e.g., white blood cell/immune system disorder).

In Vivo Gene Therapy

Gene therapy is carried out inside the body, where a functional gene is delivered directly into the patient via a vector or spray (ex: vision problems, a specific type of childhood blindness, and spinal muscular atrophy)