Which process primarily occurs in the ribosomes during protein synthesis?

The process that primarily occurs in the ribosomes during protein synthesis is translation. In translation, the ribosomes read the messenger RNA (mRNA) that has been transcribed from DNA. They use the information encoded in the mRNA to synthesize proteins by linking together the appropriate amino acids in the order specified by the mRNA sequence.

During this process, transfer RNA (tRNA) molecules bring specific amino acids to the ribosome, and the ribosome facilitates the formation of peptide bonds between these amino acids, ultimately creating a polypeptide chain that will fold into a functional protein. Therefore, translation is essential for protein synthesis and takes place directly at the ribosomes, highlighting their crucial role in the central dogma of molecular biology.

Transcription, on the other hand, occurs in the nucleus where DNA is copied into mRNA and is not related to the ribosomes. Binary fission is a asexual reproduction process used by prokaryotic organisms, and cell division generally refers to the process of mitosis or meiosis in eukaryotic cells, neither of which directly describes the synthesis of proteins at ribosomes.