Genetic Engineering and Recombinant DNA Technology Lecture Notes

These flashcards cover the vocabulary of genetic engineering, specifically the enzymes, nomenclature, and cloning vectors used in recombinant DNA technology.

Recombinant DNA

The formation of DNA created by joining foreign DNA to a plasmid using ligase enzymes.

Lysing enzymes

Enzymes used to open cells or dissolve the cell wall to obtain DNA for genetic experiments.

Lysozyme

The lysing enzyme used to dissolve the cell wall of a bacterial cell.

Cellulase and Pectinase

Lysing enzymes used to dissolve the cell wall of a plant cell.

Chitinase

The lysing enzyme used to dissolve the cell wall of a fungal cell.

Cleaving enzymes

General term for enzymes, also called nucleases, used for cutting DNA molecules into segments or opening circular plasmid DNA.

Exonucleases

Nucleases that cut DNA at any point within the ends of the DNA molecules, specifically from the $5'$ or $3'$ end.

Endonucleases

Nucleases that make internal cuts within the DNA strands.

Restriction Endonucleases

Also known as molecular scissors or chemical scalpels, these enzymes cut DNA at specific sites into fragments.

Palindromes in DNA

A sequence of base pairs in double stranded DNA that read the same in the $5' \rightarrow 3'$ direction and the $3' \rightarrow 5'$ direction.

Hind II

The first restriction endonuclease discovered; isolated by Hamilton Smith in $1970$ from the bacterium Haemophilus influenzae.

Eco R I

A restriction enzyme discovered by Arber, Smith, and Nathans in $1970$; it recognizes the palindromic sequence $5' \text{-GAATTC-} 3'$.

Restriction site

The specific site consisting of $4-8$ base pair palindromic sequences recognized by a restriction enzyme; also called a recognition site or cloning site.

Type II Restriction endonucleases

The only class of restriction enzymes used in rDNA technology because they require no ATP for cleavage and make cuts in both DNA strands.

Sticky ends

Staggered or cohesive cuts that generate protruding single stranded ends; these are more preferred in rDNA technology.

Blunt ends

Even cuts where both DNA strands are cut at the same site, generating flush ends; for example, those produced by AluI or HindII.

Synthesizing enzymes

Enzymes used to create new strands of DNA, including Reverse transcriptase and DNA polymerase.

DNA ligase

Known as molecular glue, these enzymes join DNA fragments by forming phosphodiester bonds between the $3' \text{OH}$ end and the $5' \text{P}$ end.

Cloning Vectors

Also called vehicle DNA, this is DNA used as a carrier for transferring foreign DNA into a host cell for replication.

Origin of replication (Ori)

A specific DNA sequence where replication starts and which controls the copy number of the linked DNA.

Selectable marker

A gene, such as an antibiotic resistance gene (ampicillin, tetracycline), that helps identify and favor transformants while eliminating non-transformants.

Transformation

The procedure by which a piece of DNA is introduced into a host bacterium.

Plasmids

Double stranded, extra chromosomal circular DNA found in the cytoplasm of bacteria that are capable of autonomous replication.

BAC and YAC

Artificial chromosomes (Bacterial Artificial Chromosome and Yeast Artificial Chromosome) used as cloning vectors.