What role does rRNA (ribosomal RNA) play in the cell?

Ribosomal RNA, or rRNA, plays a crucial role in the formation of ribosomes, which are the cellular machinery responsible for protein synthesis. Ribosomes consist of rRNA and proteins and are found either floating freely in the cytoplasm or attached to the endoplasmic reticulum. The rRNA molecules help maintain the structural integrity of ribosomes and provide a site for the translation of messenger RNA (mRNA) into proteins.

By facilitating the assembly of ribosomal subunits, rRNA ensures that the ribosome can function effectively during the translation process. This is key to synthesizing proteins, as ribosomes read the sequence of the mRNA and use tRNA (transfer RNA) to add the corresponding amino acids to the growing polypeptide chain. Therefore, while rRNA is fundamentally involved in protein synthesis, its primary role is in forming and functioning as part of the ribosomes.