during translation, the amino acid detaches from the transfer RNA attaches to the end of a growing protein chain when?
During translation, the amino acid detaches from the transfer RNA (tRNA) and attaches to the end of a growing protein chain when the ribosome reaches a stop codon on the mRNA molecule. This process is a part of the elongation phase of translation.
To understand this in more detail, let's break it down step by step:
1. Translation begins when the ribosome binds to the start codon (usually AUG) on the mRNA molecule. This marks the initiation stage.
2. The ribosome then moves along the mRNA molecule, reading the codons (three-nucleotide sequences) in a sequential manner.
3. As each codon is read, the corresponding tRNA molecule brings the specific amino acid that corresponds to that codon. The amino acid is attached to the tRNA molecule.
4. The ribosome catalyzes the formation of a peptide bond between the amino acid carried by the tRNA and the growing protein chain.
5. This process continues along the mRNA molecule, with each codon being read and the corresponding amino acid being added to the growing protein chain.
6. When the ribosome encounters a stop codon (UAA, UAG, or UGA), it signals the end of translation. At this point, a release factor protein binds to the ribosome, causing the detachment of the final amino acid and the release of the completed protein chain.
In summary, the detachment of the amino acid from the tRNA and its attachment to the end of a growing protein chain occurs when the ribosome reaches a stop codon during translation.