Eukaryotic ribosomes contain four different rRNA molecules : 18S , 5.8 S , 28S and 5S rRNA .
Ribosomal RNA ( rRNA ) is the catalytic component of the ribosomes .
Eukaryotic ribosomes contain four different rRNA molecules : 18S , 5.8 S , 28S and rRNA   .
Ribosomal RNA ( rRNA ) is the catalytic component of the ribosomes .