Final answer:
The ternary elongation complex during translation elongation includes an aminoacyl-tRNA, EF-1, and GTP. EF-1 and GTP work together to deliver the aa-tRNA to the ribosomal A site, where GTP hydrolysis facilitates elongation. In the initiation phase, the eIF-2 forms a ternary complex with met-tRNAi and GTP to start protein synthesis.
Step-by-step explanation:
The ternary elongation complex during translation elongation is comprised of an aminoacyl-tRNA (aa-tRNA), elongation factor 1 (EF-1), and guanosine triphosphate (GTP). During this phase of protein synthesis, EF-1 bound to GTP transports the aa-tRNA to the ribosome's A site. Once the correct match between the tRNA anticodon and the mRNA codon is established, GTP is hydrolyzed to GDP and phosphate, which facilitates the tight binding of the aminoacyl-tRNA to the A site.
Elongation factors and the hydrolysis of GTP power the translation process. For sustainable protein synthesis, another elongation factor referred to as EF-2 or EF-G in prokaryotes, binds GTP and is involved in translocating the ribosome along the mRNA. This translocation moves the peptide-bound tRNA from the A site to the P site, and the empty tRNA then exits the ribosome from the E site.
In the case of eukaryotic initiation, the formation of a ternary complex involves eukaryotic initiation factor 2 (eIF-2) binding to methionine initiator tRNA (met-tRNAi) in a GTP-dependent manner. This ternary complex then plays a crucial role in the initiation of translation by delivering the initiator tRNA to the ribosome's P site.