2.3.7 Translation Flashcards
Translation Process
Translation occurs in the cytoplasm of the cell
After leaving the nucleus via a nuclear pore, the mRNA molecule attaches to a ribosome
In the cytoplasm, there are free molecules of tRNA (transfer RNA)
These tRNA molecules have a triplet of unpaired bases at one end (known as the anticodon) and a region where a specific amino acid can attach at the other
- there are about 20 different tRNA molecules, with each a specific anticodon and specific amino acid binding site
The tRNA molecules bind with their specific amino acids (also in the cytoplasm) and bring them to the mRNA molecule on the ribosome
The triplet of bases (anticodon) on each tRNA molecules pair with a complementary triplet (codon) on the mRNA molecule
2 tRNA molecule fit onto the ribosome at any one time, brining the amino acid they are each carrying side by side
A peptide bond is formed (via a condensation reaction) between the 2 amino acids
This process continues until a ‘stop’ codon on the mRNA molecule is reached
- this acts as a signal for translation to stop and at this point the amino acid chain coded for by the mRNA molecule is complete
The amino acid chain then forms the final polypeptide
