Ch.8 Interactive Glossary Flashcards
A agent that causes tumors in humans.
Carcinogen
A bacterial protein toxic to other bacteria.
Bacteriocin
A change in the characteristic of an organism arising from a permanent alteration of a DNA sequence in a gene.
Mutation
A diagnostic procedure used to detect potential cancer agents by their ability to cause back mutations in Salmonella cells.
Ames test
A molecule of RNA that unites with amino acids and transports them to the ribosome during protein synthesis.
Transfer RNA (tRNA)
A mutant cell that has regained a physiological or biochemical property.
Revertant
A mutant selection technique where one identifies colonies missing on a minimal medium plate.
Negative selection
A mutation arising from a mutagenic agent used under controlled laboratory conditions.
Induced mutation
A mutation that arises from chance events in the environment.
Spontaneous mutation
A nucleotide segment removed after transcription of a eukaryotic messenger RNA.
Intron
A segment of DNA that forms a copy of itself, after which the copy moves into areas of gene activity to interrupt the genetic coding sequence.
Insertion sequence
A segment of DNA that moves from one site on a DNA molecule to another site, carrying information for protein synthesis; also known as a jumping gene.
Transposon
A segments of DNA resulting from discontinuous DNA replication.
Okazaki fragment
A selection technique where one is looking for colonies growing on a minimal medium plate.
Positive selection
A small, circular DNA molecule that occurs frequently in bacteria and carries genes for drug resistance; also called R factor.
R plasmid
A small, closed-loop molecule of DNA apart from the chromosome; plasmids carry genes for drug resistance and pilus formation, and are used in genetic engineering techniques.
Plasmid
A three-base sequence on the mRNA molecule that specifies a particular amino acid in the protein molecule.
Codon
A three-base sequence on the tRNA molecule that binds to the codon on the mRNA molecule during translation.
Anticodon
A type of DNA replication in which a strand of DNA “rolls off” the loop and serves as a template for the synthesis of a complementary strand of DNA.
Rolling circle mechanism
An alteration in the genetic information in a microorganism arising from the acquisition of DNA; in bacterial cells, recombination occurs by transformation, conjugation, or transduction.
Recombination
An enzyme that catalyzes DNA replication by combining complementary nucleotides to an existing template strand.
DNA polymerase
An enzyme that catalyzes RNA synthesis by combining complementary nucleotides to one strand of a gene.
RNA polymerase
An enzyme that joins together separate Okazaki fragments during DNA replication.
DNA ligase
An organism that contains all its nutritional needs in the medium.
Auxotroph
An organism that lacks a nutritional need.
Prototroph
An RNA transcript containing the information for synthesizing a specific polypeptide.
Messenger RNA (mRNA)
An RNA transcript that forms part of the ribosome’s structure.
Ribosomal RNA (rRNA)
One of the genes transcribed in an operon.
Structural gene
That portion of an operon where a repressor protein binds.
Operator
That portion of an operon where the RNA polymerase binds.
Promoter
The biochemical process in which RNA is synthesized according to a code supplied by the bases of a gene in the DNA molecule.
Transcription
The biochemical process in which the code on the mRNA molecule is translated into a sequence of amino acids in the protein molecule.
Translation
The complete set of genes in a virus or an organism.
Genome
The continuous strand synthesized during DNA replication.
Leading strand
The discontinuous strand synthesized during DNA replication.
Lagging strand
The doctrine stating that DNA is transcribed into RNA, which is then translated into protein.
Central dogma
The first codon (AUG) translated in a mRNA.
Start codon
The form of gene control where a repressor protein binds to an operator unless inhibited; the lactose (lac) operon is an example.
Negative control
The gene outside an operon that codes for a repressor protein.
Regulatory gene
The genetic material of all cells and some viruses.
Deoxyribonucleic acid (DNA)
The last codon (UGA, UAA, or UAG) in an mRNA read but not translated by a ribosome.
Stop codon
The mature eukaryotic mRNA produced after introns have been removed.
Exon
The protein that binds to the operator in an operon.
Repressor protein
The twisting and tight packing of the DNA into a chromosome.
Supercoiling
The type of replication carried out by all organisms where each double helix is composed of one old and one new polynucleotide strand.
Semiconservative replication
The unit of bacterial DNA that controls and expresses a particular set of structural genes.
Operon
