Final answer:
Ribosomes are composed of rRNA and proteins, with rRNA playing structural and enzymatic roles in protein synthesis. Ribosomal RNA is synthesized in the nucleolus, and ribosomes can be attached to the rough endoplasmic reticulum or free-floating in the cytoplasm.
Step-by-step explanation:
Ribosomes are composed of rRNA and protein. The rRNA, which makes up about 60% of the ribosome's mass, provides the site for mRNA binding and aligns the mRNA with tRNA during protein synthesis. It also possesses peptidyl transferase activity, crucial in catalyzing the peptide bonds between amino acids. The discovery of the structural and enzymatic roles of rRNA in ribosomes by scientists like Thomas Steitz earned them the Nobel Prize in Chemistry in 2009.
The RNA components of ribosomes, including rRNA, are synthesized in the nucleolus of a cell. Ribosomes are then assembled from rRNA and proteins and are found in the cytoplasm, either free-floating or attached to the rough endoplasmic reticulum, facilitating protein synthesis destined for the Golgi apparatus.