Transcription and Translation Flashcards
gene expression
the process by which DNA directs protein synthesis, includes two stages: transcription and translation
transcription
the synthesis of RNA under the direction of DNA
what produces messenger RNA
(mRNA)
transcription
ribosomes
the sites of translation
translation
the synthesis of a polypeptide, which occurs under the direction of mRNA
RNA processing
how eukaryotic RNA transcripts are modified
primary transcript
the initial RNA transcript from any gene
central dogma
the concept that cells are governed by a cellular chain of command: DNA
→ RNA → protein
how many amino acids and nucleotide bases are there
20 amino acids, 4 bases
triplet code
a series of nonoverlapping, three-nucleotide words
template strand
one of the 2 DNA strands that provides a template for ordering the sequence of nucleotides in an RNA transcript
codons
the mRNA base triplets that are read in the 5’ to 3’ direction
what does each codon do
specifies the amino acid to be placed at the corresponding position along a
polypeptide
what does each codon specify
the addition of one of 20
amino acids
how do you read codons
in the correct reading frame (triplet groups)
RNA polymerase
catalyzes RNA synthesis and pries the DNA strands apart and hooks together the RNA nucleotides
promoter
the DNA sequence where RNA polymerase attaches
terminator
the sequence signaling the end of transcription
transcription unit
the stretch of DNA that is transcribed
three stages of transcription
– Initiation
– Elongation
– Termination
transcription factors
mediate the binding of RNA polymerase and the initiation of
transcription
transcription initiation complex
the completed assembly of transcription factors and RNA polymerase II bound to a promoter
TATA box
a promoter that is crucial in forming the initiation complex in eukaryotes
how does RNA polymerase work
moves along the DNA, it untwists the double helix, 10 to 20 bases at a time