What are ribosomes primarily made up of?

Ribosomes are primarily composed of protein and ribonucleic acid (RNA). Their structure includes both ribosomal RNA (rRNA) and ribosomal proteins, which come together to form functional ribosomes. The rRNA is critical for the ribosome's role in protein synthesis, providing the scaffold for the ribosomal proteins to attach and playing an essential role in the catalytic activity during translation, where amino acids are linked together to form proteins.

The presence of both RNA and protein contributes to the ribosome's dual functionality: it not only serves as a site for decoding mRNA (the messenger RNA that carries genetic information) into proteins, but it also assists in the formation of peptide bonds between amino acids. This combination of molecules enables ribosomes to be versatile and essential components of all living cells, reflecting their pivotal role in the central dogma of molecular biology, which describes how genetic information flows from DNA to RNA to protein.