Final answer:
The movement of ribosomes in which the tRNA shifts from the A to P to E site during protein synthesis is known as translocation, facilitated by elongation factor-G and is GTP-dependent.
Step-by-step explanation:
Movement of the ribosome so that the tRNA in the P site is shifted to the E site while the tRNA in the A site is shifted to the P site is called translocation. This process occurs during the elongation phase of protein synthesis, where the ribosome moves along the mRNA in the 5' to 3' direction. The movement is facilitated by elongation factor-G (EF-G), which also goes by the name translocase. This GTP-dependent conformational change allows the growing polypeptide chain to be handed over from the tRNA at the A site to the P site, and for the now deacylated tRNA at the P site to move to the E site.
The energy for the translocation and peptide bond formation comes from the hydrolysis of GTP provided by elongation factors. As this cycle repeats with each codon, the polypeptide chain elongates, and tRNAs move from A to P to E sites until a stop codon is encountered, which signals the termination of translation.