Plasmids and Recombinant DNA Theory

Vocabulary-style flashcards covering the properties, replication, and segregation of plasmids, as well as their use in genetic engineering through restriction enzymes and gel electrophoresis.

Plasmids

Circular DNA molecules, smaller than chromosomes, found in bacteria, archaea, and eukaryotic microbes that possess a separate Ori and primarily encode genes for survival.

Low-copy-number plasmids

Plasmids that ensure their inheritance by segregating equally to daughter cells during division.

High-copy-number plasmids

Plasmids that segregate randomly to daughter cells during division.

Bidirectional replication

A replication method that starts at a single origin and occurs in two directions simultaneously.

Rolling-circle replication

A replication method that starts at a single origin and moves in only one direction, beginning with a nick in one strand.

ParM

An actin-like protein that forms long filaments to drive plasmids towards opposite poles, ensuring stable segregation.

Green Fluorescent Protein (GFP)

A protein originally from Jellyfish that can be encoded in plasmids and expressed in bacteria for genetic engineering applications.

Restriction endonucleases

Bacterial enzymes, also known as "Molecular scissors," used to cut foreign DNA at specific restriction sites.

Restriction site palindromes

DNA sequences that read the same on both strands in the $5'-3'$ direction, such as SmaI ($5'-CCCGGG-3'$) and EcoRI ($5'-GAATTC-3'$).

Blunt ends

Uniform DNA ends produced by restriction enzymes like AluI (from Arthrobacter luteus) and HaeIII (from Haemophilus aegyptius).

Sticky ends

Cohesive DNA ends produced by restriction enzymes like BamHI, HindIII, and EcoRI that can anneal to complementary strands.

DNA ligase

An enzyme used in the formation of recombinant DNA to seal the nicks between the annealed DNA fragments.

Chimeric plasmid

A plasmid vector that contains an inserted fragment of foreign DNA, also referred to as a plasmid chimera.

DNA Gel Electrophoresis

A technique used to examine DNA where negatively charged fragments migrate toward a positive (+) pole, with smaller fragments moving faster than larger ones.