Gene Expression and Protein Synthesis Flashcards
(25 cards)
Information contained in DNA molecules is expressed in the structure of proteins.
The central dogma of molecular biology:
is the turning on or activation of a gene.
Gene expression
The process in which information encoded in a DNA molecule is copied into an mRNA molecule.
Transcription
catalyze transcription: poly I for rRNA formation, poly II for mRNA formation, and poly III for tRNA formation.
polymerases (poly)
catalyzes the formation of most of the rRNA.
RNA polymerase I (pol I)
catalyzes mRNA formation
Pol II
catalyzes tRNA formation as well as one ribosomal subunit.
Pol III
that is transcribed into RNA; the structural gene is made of exons and introns.
A structural gene
that controls transcription; the regulatory gene is not transcribed but has control elements, one of which is the promoter.
A regulatory gene
There is always a sequence of bases on the DNA strand called an ___________.
initiation signal.
RNA polymerase zips up the complementary bases in a process called _____________.
elongation
Triplets of bases on mRNA are called _________.
codons.
At the opposite end of the tRNA molecule is a ______.
codon recognition site.
The codon recognition site is a sequence of three bases called an ________.
Anticodon.
serve as termination signals.
UAA, UAG, and UGA
The various methods used by organisms to control which genes will be expressed and when.
Gene regulation
An error in the copying of a sequence of bases.
Mutation
: a chemical that causes a base change or mutation in DNA.
Mutagen
Many changes in base sequence caused by radiation and mutagens do not become mutations because cells have repair mechanisms called ___________.
nucleotide excision repair (NER).
DNA from two sources that have been combined into one molecule.
Recombinant DNA
A small, circular, double-stranded DNA molecule of bacterial origin.
Plasmid
cleave DNA at specific locations.
restriction endonucleases
is a technique whereby a missing gene is replaced by a viral vector.
Gene therapy
cells are removed from a patient, given the missing gene, and then the cells are given back to the patient.
ex vivo gene therapy
