TRANSLATION Flashcards
What happens in translation?
the transfer of genetic information from mRNA into amino acids
PROCESS
-mRNA enters cytoplasm, associates with a ribosome, binding to the small subunit of the ribosome at the start codon (AUG)
-the first tRNA molecule with the complementary anticodon (UAC) then binds to the start codon by hydrogen bonding
-the first tRNA molecule carries the amino acid METHIONINE
-the large subunit of the ribosome binds and translation can begin
-once the ribosome is fully assembled, the second tRNA molecule with a complementary anticodon is able to bind to the next mRNA codon
-a peptide bond is then formed between the two amino acids, forming a dipeptide and releasing the methionine from the first tRNA (using energy from ATP)
-ribosome moves along by exactly 3 bases/1 codon and the first tRNA is released
-process repeats, forming a long polypeptide
-once a ribosome has moved along the mRNA strand away from the start codon, another ribosome is able to attach to the start codon- this results in many identical polypeptides being synthesised simultaneously from the same mRNA strand
-there’s no tRNA anticodons complementary to the stop codons so once a stop codon is reaches, no tRNA molecules can bind and the synthesised polypeptide chain is released from the last tRNA molecule
-the ribosome units separate from the mRNA strand and are quickly reused for another round of translation
-meanwhile the polypeptide coils and folds into a specific tertiary structure, determined by the amino acid sequence or can connect to other polypeptide chains and/or prosthetic groups to form the quaternary structure
