Ribosomal RNA is more often than not the least discussed of the three types of RNA required for protein synthesis. The three types of RNA involved in protein synthesis are transfer RNA (tRNA), messenger RNA (mRNA), and ribosomal RNA (rRNA). All three types of RNA are equally important in protein synthesis because protein synthesis won't occur without all three types of RNA present.
Ribosomal RNA is produced in the nucleolus, which is a specialized region of a cell's nucleus, and rRNA is a main component of ribosomes (the cellular unit where protein synthesis occurs). In fact, rRNA makes up more than 60 percent of the weight of all ribosomes.
Protein synthesis can be broken down into two main parts. The first part is transcription, and the second part is translation. Transcription occurs in the nucleus and involves the creation of the mRNA strand. DNA doesn't leave the nucleus, but DNA's message does leave the nucleus. The DNA message is essentially written down in RNA format, and that RNA strand acts as a messenger that takes the DNA message from the nucleus to the ribosome.
The mRNA sequence then needs to be translated in order to produce a protein. The sequence is read in units of three bases at a time called codons. A codon corresponds to a specific amino acid that is carried by the tRNA. The anti-codon of the tRNA matches up with the codon of the mRNA, and the amino acid "breaks off" of the tRNA. This process will repeat until an entire amino acid sequence is complete, at which point we call it a polypeptide chain, or protein. The rRNA helps during the translation portion of protein synthesis by binding to mRNA. The rRNA will also "recruit" tRNA that matches the mRNA. Finally, the rRNA will also catalyze the formation of bonds between the amino acids.