What is the structure of rRNA?

Ribosomal RNA (rRNA) consist of 2 subunits: a large subunit and a small subunit. In prokaryotes, the large subunit is called 50S and the small subunit is called 30S. In eukaryotes, the large subunit is called 60S and the small subunit is called 40S. 

rRNA has a complex secondary structure, characterized by the formation of helices, loops, and other structural elements. These secondary structures are crucial for the proper functioning of the ribosome during protein synthesis. In eukaryotes, there can be between 50 to 5,000 sets of rRNA genes and as many as 10 million ribosomes in one cell. On the other hand, prokaryotic cells typically have fewer sets of rRNA genes and ribosomes per cell.