What is a major function of the ribosomes in a cell?

• A. Energy production
• B. Protein synthesis
• C. Transport of substances
• D. DNA replication

Answer: (B)

Ribosomes play a crucial role in the process of protein synthesis, which is fundamental to cellular function. They are molecular complexes made up of ribosomal RNA (rRNA) and proteins that facilitate the translation of messenger RNA (mRNA) into polypeptide chains, ultimately leading to the formation of proteins. During translation, ribosomes read the sequence of codons in the mRNA and assemble the corresponding amino acids in the correct order to create a functional protein.

This process occurs in two major stages: initiation, where the ribosome assembles around the start codon of the mRNA; and elongation, where amino acids are sequentially added to the growing polypeptide chain. The accuracy and efficiency of this process are vital because proteins carry out a myriad of functions in biological systems, including acting as enzymes, providing structural support, and serving in signaling pathways. Thus, the primary function of ribosomes is indeed to synthesize proteins, making them essential components of all living cells.