Summary
The three stages of translation: assembly at the start codon, chain growth, and release at a stop codon.
In depth
Initiation: small subunit binds mRNA at the start codon with initiator tRNA (Met), then the large subunit joins. Elongation cycles through aminoacyl-tRNA arrival, peptide bond formation and translocation. Termination: a release factor recognises a stop codon, and the polypeptide is freed.
Energy comes from GTP hydrolysis by elongation factors.
Initiation in eukaryotes needs many factors (eIFs) to scan from the 5 prime cap to the first AUG in good context; eIF2 delivers the initiator tRNA with GTP. Elongation needs elongation factors for tRNA delivery and for translocation, which moves the ribosome three bases along the message, and each step uses GTP.
Termination uses release factors (RF1 and RF2 in bacteria, eRF1 in eukaryotes) which mimic tRNA and trigger hydrolysis of the peptidyl-tRNA bond, and the subunits are recycled. The overall cost is at least four high-energy phosphate bonds per peptide bond.
Example: diphtheria toxin inactivates eEF2 and halts protein synthesis in human cells.
Frequently asked questions
What is Initiation, Elongation, Termination?
The three stages of translation: assembly at the start codon, chain growth, and release at a stop codon.
Which area of biology covers Initiation, Elongation, Termination, and how advanced is it?
Initiation, Elongation, Termination is one of the 52 topics in Molecular Biology. It is rated Intermediate, so it suits learners who already know the core vocabulary. Related topics in this area include Translation, Ribosome Structure, RNA Polymerase.
Can you give an example of Initiation, Elongation, Termination?
Translation of an average protein of 300 amino acids takes about 20 seconds in bacteria.
What should I learn before Initiation, Elongation, Termination?
Work through the Beginner topics in Molecular Biology first, such as Central Dogma, DNA Replication, Base Pairing, then return to Initiation, Elongation, Termination. Intermediate topics assume the Beginner vocabulary.
What topics are related to Initiation, Elongation, Termination?
The closest topics to Initiation, Elongation, Termination are Translation, Ribosome Structure, RNA Polymerase, Trp Operon. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Initiation, Elongation, Termination?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Initiation, Elongation, Termination. To practise the whole of Molecular Biology, use the Molecular Biology quiz.
How is Initiation, Elongation, Termination different from Translation?
Initiation, Elongation, Termination: The three stages of translation: assembly at the start codon, chain growth, and release at a stop codon. Translation: Ribosomes read the mRNA codons to assemble amino acids into a protein. Read both side by side and note what each one explains.
How should I study Initiation, Elongation, Termination step by step?
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Translation and explain the difference aloud. Finally, take the Molecular Biology quiz and come back to this page for any question you miss.