Final answer:
In each cycle of elongation, at least two molecules of GTP are hydrolyzed to provide the energy needed for protein synthesis.
Step-by-step explanation:
In each cycle of elongation, at least two molecules of GTP are hydrolyzed. GTP (guanosine triphosphate) provides the energy needed for the ribosome to move along the mRNA and add the next amino acid to the growing polypeptide chain. The hydrolysis of GTP releases the energy required for these processes to occur.