What is the function of ribosomes in prokaryotic cells?

Ribosomes play a crucial role in protein synthesis within prokaryotic cells. They are the cellular machinery responsible for translating messenger RNA (mRNA) sequences into polypeptide chains, which ultimately fold into functional proteins. In prokaryotes, ribosomes are present in the cytoplasm and are composed of ribosomal RNA (rRNA) and proteins. The process of translation involves the ribosome reading the codons on the mRNA and facilitating the binding of transfer RNA (tRNA) molecules that carry specific amino acids, thereby stringing these amino acids together into a polypeptide according to the mRNA instructions.

This function is essential for cellular function and survival since proteins are necessary for a wide array of biological processes, including enzyme activity, structural support, and regulation of cellular pathways. Thus, the primary and defining role of ribosomes in prokaryotic cells is indeed protein synthesis.