A ribosome slides along messenger RNA, reading three-letter codons one at a time. Each codon is matched by a transfer RNA (tRNA) carrying the corresponding amino acid; the ribosome links each new amino acid to the growing polypeptide chain until it reaches a stop codon.
codon (3 nt) → anticodon match → amino acid added
elongation_rate ∝ speed · tRNA_availability
P(error per codon) = mutation_rate
- Translation speed — how fast the ribosome advances codon-by-codon along the mRNA strand.
- tRNA availability — fraction of needed tRNAs present in the cell; scarcity stalls the ribosome, slowing elongation.
- Mutation rate — chance each codon is mis-read, inserting a wrong (red) amino acid into the chain — a visual model of translation errors.
- Restart mRNA strand — resets the ribosome to the start codon and clears the polypeptide chain.
Real-world: this two-step process (DNA transcription → mRNA, then ribosome translation → protein) is the core of the "central dogma" of molecular biology, and translation-blocking is how many antibiotics selectively kill bacteria.