What do ribosomes synthesize?

Ribosomes are vital cellular structures that play a key role in the process of translation, which is part of protein synthesis. They are composed of ribosomal RNA (rRNA) and proteins, and their primary function is to facilitate the assembly of amino acids into polypeptide chains, ultimately forming proteins. During translation, the ribosome reads the messenger RNA (mRNA) sequence and, using transfer RNA (tRNA) to bring in the appropriate amino acids, links them together according to the genetic code. This process is crucial for producing the proteins that serve various functions in the cell, including structural, enzymatic, and signaling roles. Therefore, ribosomes synthesize proteins, making this choice the correct answer.