W1(2): Eukaryotic Protein Synthesis Flashcards
ribosome
large assembly of RNAs & proteins that synthesizes proteins under direction of an mRNA template
translation
Synthesis of a protein on an mRNA template
main diff btwn gene expression in bacteria & euks
bacteria: T&T coupled
euks: multistage & compartmentalised
tRNA
an RNA intermediate in PS that interprets the genetic code
Each molecule can be linked to an aa
Has an anticodon seq that’s complementary to a triplet codon representing an aa
peptide bond
covalent bond linking 2 consec aa monomers along a peptide/protein chain
(carboxyl group of 1 aa molecule reacts w/ amino group of other aa)
Aminoacyl-tRNA
tRNA bound to an aa
Peptidyl-tRNA
tRNA to which the nascent polypeptide has been transferred following peptide-bond synthesis during polypeptide translation
codon
a triplet of nucleotides that codes for an aa or is a translation termination signal
nascent polypeptide
the translation process needs:
ribosome
mRNA: brings pp-coding info to rib
tRNA: aminoacytyl-tRNA that delivers aas for PS
translation factors
what are the 3 categories of translation factor?
Initiation factors (IFs)
Elongation factors (EFs)
Release factors (RFs)
where does translation of mRNA occur?
ribosomes
where are ribosomes located?
Freely localized to cytoplasm or bound to RER
what is the structure of a ribosome?
Large ribonucleoprotein particles that contain more RNA (by mass) than protein & dissociate into large & small subunits
which ribosomal subunit is mRNA assoc w/?
small
