Protein synthesis W4 Flashcards
what is translation
synthesis of protein under direction of mRNA
what three components does translation require
mRNA
tRNA
rRNA
what is the broad role of mRNA
acts as a template
broad role of tRNA
acts as an adaptor
broad role of rRNA
the protein making machine
definition of protein synthesis
joining amino acids by peptide bonds
what is tRNA
specialised RNA molecule that acts as an adaptor between amino acid and mRNA
what is a ribonucleoprotein
a ribosome
what is a ribosome made out of
rRNA and protein
what is the rhibosome small subunit
the bottom part of a ribosome
what does a ribosome hold together (3)
polypeptide chain, tRNAand mRNA
what are the two components of a ribosome
ribosome small subunit
ribosome large subunit
the …… loop of the tRNA base
pairs with the … in the mRNA
anticodon loop in tRNA base pairs with the codon in mRNA
what is the anticodon loop
the bottom part of tRNA that contains 3 bases that pair with the codon in mRNA
to which part of the tRNA does the specific amino acid bind to
the 3’ `end
describe the process of translation vague steps
1 ribosome binds to mRNA
- tRNA floating around in cell binds to corresponding AAs
- tRNA bound to amino acid enters ribosome at Asite
- at the p-site PEPTIDYL TRANSFERASE catalyses formation of peptide bond betwee amino acid in A site and P site
- empty tRNA leaves via E site
what is the name of the enzyme found at the P site
peptidyl transferase
where to start and finish making a protein
start codon AUG
stop codon UGA
UAG
UAA
all protein synthesis begins on ….ribosomes found in cytosol
free
where is the n terminal
mRNA
what does the N terminal dictate
whether protein synthesis will continue of free ribosome or the ribosome will need to bind to rER
what are the two possible broad destinations of proteins give two examples off each
intracellular (egmitochondria or cytosol
extracellular eg secreted from cell or membrane proteins
what happens to translation one N signal sequence is detected
translation pauses until ribosome attaches to the rER
process of n signal sequence (4 steps)
signal sequence synthesised
signal binds to signal recognition particle
signal recognition particle binds to signal recognition particle receptor on rER membrane
protein continuesto synthesise into lumen of rER
role in disease
alzheimer’s amyloid plaques
prion diseases
diamond-blackfan anemia
treacher collins syndrom
