Which component of the cell is primarily responsible for the synthesis of proteins?

The component of the cell primarily responsible for the synthesis of proteins is ribosomes. Ribosomes are molecular machines found within all living cells that facilitate the translation process, where messenger RNA (mRNA) is decoded to produce polypeptide chains, which then fold into functional proteins.

Ribosomes can be found freely floating in the cytoplasm or attached to the endoplasmic reticulum (ER), which is known as rough ER due to the presence of these ribosomes. This attachment plays a critical role in the synthesis of proteins that are destined for export out of the cell or for use in the cell membrane.

By contrast, the nucleus serves as the control center of the cell by housing genetic information and is responsible for the transcription of DNA into mRNA, the first step in protein synthesis. Mitochondria are primarily involved in energy production through cellular respiration, and the Golgi apparatus functions in processing and packaging proteins for transport. However, none of these organelles are directly involved in the actual synthesis of proteins, which is the specific function of ribosomes.