Transcription and Translation Flashcards
coding strand
The strand of DNA that is not transcribed during synthesis of RNA. Its sequence corresponds to that of the mRNA produced from the other strand.
What is the difference between RNA and DNA polymerase?
RNA polymerase does not require a primer
initiation
In an enzyme-catalyzed reaction, the stage during which enzymes orient reactants precisely as they bind at specific locations within the enzyme’s active site.
holoenzyme
A multipart enzyme consisting of a core enzyme (containing the active site for catalysis) along with other required proteins.
core enzyme
The enzyme responsible for catalysis in a multi-part holoenzyme.
promoters
A short nucleotide sequence in DNA that binds RNA polymerase, enabling transcription to begin. In prokaryotic DNA, a single promoter often is associated with several contiguous genes. In eukaryotic DNA, each gene generally has its own promoter.
downstream
In genetics, the direction in which RNA polymerase moves along a DNA strand.
upstream
n genetics, opposite to the direction in which RNA polymerase moves along a DNA strand.
TATA box
A short DNA sequence in many eukaryotic promoters, about 30 base pairs upstream from the transcription start site.
elongation
elongation
(1) The process by which messenger RNA lengthens during transcription. (2) The process by which a polypeptide chain lengthens during translation.
termination
In enzyme-catalyzed reactions, the final stage in which the enzyme returns to its original conformation and products are released.
primary transcript
In eukaryotes, a newly transcribed messenger RNA molecule that has not yet been processed (i.e., it has not received a 5¢ cap or poly(A) tail, and still contains introns).
exons
A region of a eukaryotic gene that is translated into a peptide or protein.
introns
A region of a eukaryotic gene that is transcribed into RNA but is later removed, so it is not translated into a peptide or protein.
splicing
The process by which introns are removed from primary RNA transcripts and the remaining exons are connected together.
poly(A) tail
In eukaryotes, a sequence of 100–250 adenine nucleotides added to the 3’ end of newly transcribed messenger RNA molecules.
What is the final step in the creation of mRNA?
an addition of cap and tail
What are the functions of caps and tails in mRNA?
protect from degradation by ribonucleuses and enhance efficacy of translation
RNA processing
In eukaryotes, the changes that a primary RNA transcript undergoes in the nucleus to become a mature mRNA molecule, which is exported to the cytoplasm. Includes the addition of a 5’ cap and poly (A) tail and splicing to remove introns.
polyribosome
A structure consisting of one messenger RNA molecule along with many attached ribosomes and their growing peptide strands.
tRNA
One of a class of RNA molecules that have an anticodon at one end and an amino acid binding site at the other. Each tRNA picks up a specific amino acid and binds to the corresponding codon in messenger RNA during translation.
aminoacyl tRNA synthases
An enzyme that catalyzes the addition of a particular amino acid to its corresponding tRNA molecule.
aminoacyl tRNA
A transfer RNA molecule that is covalently bound to an amino acid
anticodon
The sequence of three bases (triplet) in a transfer RNA molecule that can bind to a mRNA codon with a complementary sequence.
