What is the role of ribosomes in a cell?

Ribosomes play a crucial role in the process of protein synthesis, which is fundamental for the growth, repair, and maintenance of cells. They are the molecular machines that translate messenger RNA (mRNA) into polypeptide chains, which then fold into functional proteins. Ribosomes can be found freely floating in the cytoplasm or attached to the endoplasmic reticulum, where they facilitate the assembly of amino acids into proteins based on the instructions carried by mRNA.

The process begins when mRNA, transcribed from DNA, binds to the ribosome. Transfer RNA (tRNA) then brings specific amino acids to the ribosome, which are matched to the codons (triplets of nucleotides) on the mRNA strand. The ribosome moves along the mRNA, catalyzing the formation of peptide bonds between the amino acids, effectively building a growing protein chain until a stop codon is reached. This process is vital for all cellular activities since proteins serve as enzymes, structural elements, and signaling molecules, among other functions.

In contrast, the other choices do not accurately represent the primary function of ribosomes. Energy production typically involves organelles like mitochondria, DNA replication occurs in the nucleus with the assistance of various