L9- 12: Transcription and Translation Flashcards
what is promotor and terminator
when RNA polymerase makes stand to and from
what are the 4 requirements of transcription (RNA synthesis)
- four nucleoside 5’ triphosphate: 5’ATP, 5’GTP ect
- Mg 2+
- DNA template (no primer)
- RNA polymerase (RNAP)
Differences between RNA and DNA polymerase
- RNA= no primer, no helicase to unwind, higher error rate
sims between RNA and DNA polymerase
- forms phosphodiester bonds b/w nicleosides
- energy stored in bonds
what a cistron
in prokaryotic mRNA
- one poly peptide chain DNA segment
process b/w messenger RNA + pro mrna
genes with exons and introns, introns removed
function of mRNA
copy of DNA
function of rRNA
part of ribosome
function of tRNA
adapter b/w mrna and aa, aligns aa with triplet on MRNA
function of small RNA
pre-mrna splicing, transport proteins to ER
function of 5’ end capping and 3’ end polyadenylation
enables export from nucleus + binding of ribosome
where is the anti codon found
t RNA
what enables attachment of codon/anticodon
aminoacyl-trna synthetases
what are the two adapters used to translate genetic code
aminoacyl-trna synthetases= couples aa with tRNA
tRNA = anticodon forms base pair with codon of mRNA
What the synthesise example for leucine (aa)
leycyl-trna synthetases
what term describes tRNA when aa attached and what the term of the overall structure
charged or acylated
amino acyl tRNA
Describe the two sub units of ribosomes
1- small subuinit= matches tRNA to codon on mRNA
2- Large subunit= catalyses formation of peptide bonds to link aa together
what are the ribosome binding sites
= 1 binding site for mRNA and 3 for tRNA
what are the 3 tRNA binding sites on a ribosome
(A) aminoacyl- tRNA (new trna enters)
(P) peptide trna (trna attached to polypeptide chain
(E) exit= empty trna exists
explain elongation of polypeptide steps
- aminoacyl trna binds to A site, spent trna leaves E site
- new peptide bond formed (uses ATP)
- large subunits more to next codon
- small subunit moves to next= A site now empty for next aminoacyl trna
what are the 3 requirements for translation
mrna containing coding region
trna carrying amino acids
ribosomes (rrna and proteins)
3 phases of protein synthesis
initiation (mrna, ribosome, initiating trna)
elongation (peptide bonds + movement)
termination- dissociation of ribosomes and peptides
how many potential reading frames are there
3
How are ribosomes ribozymes
perform condensation at c terminal of aa at p site and n terminal of aa at a site
