Chapter 20 Flashcards
nucleic acid hybridization
the base pairing of one strand of a nucleic acid to the complementary sequence on a strand from another nucleic acid molecule
genetic engineering
direct manipulation of genes for practical purposes
DNA sequencing
determining the complete nucleotide sequence of a gene or DNA segment
DNA cloning
the production of multiple copies of a specific DNA segment
plasmid
a small, circular, double stranded DNA molecule that carries accessory genes separate from those of a bacterial chromosome; in DNA cloning, plasmids are used as vectors carrying up to 10,000 base pairs of DNA
recombinant DNA molecule
a DNA molecule made in vitro with segments from different sources
gene cloning
the production of multiple copies of a gene
cloning vector
in genetic engineering, a DNA molecule that can carry foreign DNA into a host cell and replicate there. cloning vectors include plasmids and bacterial artificial chromosomes (BACs) which move recombinant DNA from a test tube back into a cell, and viruses that transfer recombinant DNA by infection
restriction enzymes
a type of enzyme that recognizes and cuts DNA molecules foreign to a bacterium; the enzyme cuts at specific nucleotide sequences (restriction sites)
restriction site
a specific sequence on a DNA strand that is recognized and cut by a restriction enzyme
restriction fragments
a DNA segment that results from the cutting of DNA by a restriction enzyme
sticky end
a single stranded end of a double stranded restriction fragment
gel electrophoresis
a technique for separating nucleic acids or proteins on the basis of their size and electrical charge, both of which affect their rate of movement thru an electric field in a gel made of agarose or another polymer
polymerase chain reaction (PCR)
a technique for amplifying DNA in vitro by incubating it with specific primers, a heat resistant DNA polymerase, and nucleotides
expression vector
a cloning vector that contains a highly active bacterial promoter just upstream of a restriction site where a eukaryotic gene can be inserted, allowing the gene to be expressed in a bacterial cell; expression vectors are also available that have been genetically engineering for use in specific types of eukaryotic cells