Transcription - 17.1, 17.2 Flashcards
Genes provide
Instructions for making specific proteins - but not the gene
Transcription
Synthesis of RNA using information in the DNA
“rewriting”
mRNA
Transcript of the gene’s protein-building instructions
Carries genetic message from the DNA to the protein synthesizing machinery of the cell
Translation
Synthesis of a polypeptide using the information in the mRNA
mRNA to amino acid sequence of a polypeptide
Site of translation
Ribosomes - complex particles that facilitate the orderly linking of amino acids into polypeptide acids
How many amino acids
20
Triplet code
Genetic instructions for a polypeptide chain are written in the DNA as a series of non overlapping, three nucleotide words
template strand
Provides the pattern/template for the sequence of nucleotides in RNA transcrit
mRNA nucleotide triplets are called
codons
mRNA written in which direction
5’-3’
met/start codon
AUG
Stop codons
3- UAA,UGA,UAG
RNA polymerase
Pries 2 strands of DNA apart and joins together RNA nucleotide. Doesn’t need a primer
Initiation
Rna polymerase binds to promoter, DNA strands unwind, polymerase initiates RNA synthesis
Elongation
Codon recognition, peptide bond formation, translocation
Termination
RNA transcript is released, polymerase detaches from DNA
promoter
DNA sequence where RNA polymerase attaches and initiations transcription (upstream from terminator)
Terminator
Sequence that signals the end of transcription
transcription unit
Stretch of DNA downstream from the promoter that is transcribed into and RNA molecule
start point
nucleotide where RNA synthesis actually begins
transcription factors
Mediate the binding of RNA polymerase and the initiation of transcription
