What is the primary function of ribosomes in a cell?

• A. They synthesize lipids
• B. They facilitate the translation of mRNA into proteins
• C. They produce ATP
• D. They store genetic material

Answer: (B)

The primary function of ribosomes in a cell is to facilitate the translation of mRNA into proteins. Ribosomes are complex molecular machines composed of ribosomal RNA (rRNA) and proteins, and they play a crucial role in the protein synthesis process. During translation, ribosomes read the sequence of messenger RNA (mRNA) and assemble the corresponding amino acids into a polypeptide chain, ultimately forming a functional protein.

This process involves multiple steps, including the binding of mRNA to the ribosome, the recruitment of transfer RNA (tRNA) molecules that carry specific amino acids, and the formation of peptide bonds between adjacent amino acids as dictated by the mRNA sequence. Thus, ribosomes are essential for translating the genetic code into the proteins that perform countless functions within the cell.

Other options do not describe the primary role of ribosomes. For example, the synthesis of lipids is a function carried out by the smooth endoplasmic reticulum, ATP production occurs mainly in the mitochondria, and the storage of genetic material is typically associated with the nucleus in eukaryotic cells. Therefore, option B accurately reflects the primary role of ribosomes in the cell.