Translation Flashcards
Brief description of translation
DNA is transcribed into a sequence of codons on mRNA, each codon is specific to an AA, about 60 different tRNA molecules which attach to specific AA
What is Translation?
process of ribosomes constructing polypeptides from AA
Translation 1/10
A ribosome becomes attached to the starting codon (AUG) at one end of the mRNA. each ribosome can fit 2 codons at any 1 time
Translation 2/10
The tRNA molecule with the complementary anticodon sequence (UAC) moves to the ribosome and pairs up with the codon on the mRNA. this tRNA carries an aa
Translation 3/10
Another tRNA with a complementary anticodon then pairs up with the next codon this carries an AA
translation 4/10
The ribosome then moves along the mRNA molecule bringing together 2 tRNA molecules at 1 time.
translation 5/10
the 2 aa are joined by a peptide bond using an enzyme (peptidyl transferase) and ATP which is hydrolysed to provide the required energy.
translation 6/10
The ribosome then moves onto the 3rd codon in the sequence linking the aa on the 2nd and 3rd tRNA molecules together
translation 7/10
During this the 1st tRNA molecule leaves and the next is free to join from the pool in the cell
translation 8/10
this continues with up to 15 aa added each second until the chain is complete
translation 9/10
up to 50 ribosomes can pass behind the first at the same time so many identical polypeptides can be produced simultaneously
translation 10/10
the synthesis of polypeptides continues until the ribosome reaches a STOP codon. once reached the ribosome, last tRNA, and mRNA all separate and the polypeptide is complete.
