Final answer:
For mRNA translocation in prokaryotic cells, both the 30S and 50S ribosomal subunits are involved. Together, they facilitate the synthesis and movement of mRNA and tRNA during protein synthesis. The correct answer is C. Both 30S and 50S.
Step-by-step explanation:
The question pertains to the prokaryotic subunits involved in the process of translocation, where mRNA moves through the ribosome. In E. coli, which is a model organism for prokaryotic cells, the ribosomes dissociate into a small 30S and a large 50S subunit when not synthesizing proteins, and reassociate during the initiation of translation. The small 30S subunit is responsible for binding the mRNA template, but the actual translocation involves movement of the tRNAs through the A (aminoacyl), P (peptidyl), and E (exit) sites located on the large 50S subunit. The interaction between the subunits and the mRNA therefore involves both the 30S and 50S subunits.
In summary, for mRNA translocation in prokaryotic cells, both 30S and 50S subunits are involved, working together to facilitate proper synthesis and movement of the mRNA and tRNA molecules during protein synthesis. Therefore, the correct answer to the question is C. Both 30S and 50S.