What is the primary function of ribosomes in a cell?

Ribosomes play a crucial role in the process of protein synthesis, which is their primary function within the cell. They serve as the molecular machines that decode messenger RNA (mRNA) sequences to assemble amino acids into polypeptide chains, ultimately forming proteins. This process is essential as proteins are fundamental to various cellular functions, including structure, enzymatic activity, and regulation of biological processes.

During protein synthesis, ribosomes read the sequence of mRNA and facilitate the binding of transfer RNA (tRNA) that carries specific amino acids. As the ribosome moves along the mRNA strand, it catalyzes the formation of peptide bonds between the amino acids, creating a growing protein chain. This makes ribosomes vital for translating genetic information stored in DNA into functional proteins necessary for life.

Other options like energy production, DNA replication, and cell division pertain to different cellular processes. Energy production occurs primarily in mitochondria, DNA replication involves the actions of various enzymes and occurs in the nucleus, and cell division is a complex process involving multiple cellular components and signals. Thus, the alignment of ribosomes' function with protein synthesis distinguishes it as the accurate choice in this context.