Transcription and Translation Flashcards
Process of DNA to protein
DNA - mRNA transcription - mature mRNA - transport to cytoplasm - to ribosome - make protein (synthesis)
Template strand is
3’ to 5’.
aka ANTISENSE
Enzyme needed to form complementary RNA sequence from template DNA strand
RNA polymerase
Raw materials for transcription
DNA, transcription factors, RNAp, ATP.
Transcription begins at
- TATA box (i.e. promotor) and enhancer region.
2. at the TRANSCRIPTION UNIT portion of gene
TF2D factor
TBP component on it binds to TATA box on DNA.
TF2B and TF2A then attach. RNAp can now bind.
Other TF’s can bind to it to mature it.
RNAp reads from
3’ to 5’ on antisense
RNAp generates from
5’ to 3’ of new mRNA strand
TRANSLATION
tRNA function:
tRNA carries amino acids to ribosome
mRNA is read 3 bases at a time.
As each triplet (codon) is read a tRNA transfers corresponding aa to growing chain.
chain folds –> protein
1 codon =
3 bases = 1 amino acid coded for
PARTS OF A GENE: TRANSCRIPTION.
1) Promoter and beginning transcription.
On the gene itself:
PROMOTER REGION
- 25 to -30 bp’s upstream from TSS.
- has the TATA box
- RNAp binds to the promoter region
- RNAp2 - catalyzes synthesis of mRNA precursors for all protein coding genes
PARTS OF A GENE: TRANSCRIPTION.
2) pre mrna processing
DNA - primary RNA transcript - mRNA matured - into cytosol - protein.
gene –> primary transcript/pre-mRNA (addition of cap at 3’ poly A TAIL by enzyme and CAP at 5’ end by ) –> Removal of introns, joining of exons (spliceosome) –> mature mRNA
post transcriptional processing
- Cap addition at the 5’ end (5’ – 5’ triphosphate bridge)
• Capping enzyme mRNA guanylyltransferase adds a
7–methylguanylate cap; methylated cap or m7G - Poly (A) tail addition at the 3’ end
• polyadenylase - Splicing
• spliceosome
What are the parts of a gene?
PROMOTER REGION –> TSS –> START CODON – INTRONS / EXONS – STOP CODON –> POLYADENLATION SITE –> TTS
Does pre-MRNA include exons and introns?
Yes
