The largest ribonucleoprotein component of RIBOSOMES. It contains the domains which catalyze formation of the peptide bond and translocation of the ribosome along the MESSENGER RNA during GENETIC TRANSLATION.

Synonyms: Ribosomal Subunits, Large, Large Ribosomal Subunits, Subunits, Large Ribosomal, Subunit, Large Ribosomal, Large Ribosome Subunit, Ribosome Subunit, Large, Large Ribosomal Subunit, Subunits, Large Ribosome, Large Ribosome Subunits, Subunit, Large Ribosome, Ribosome Subunits, Large, Ribosomal Subunit, Large