Which structure is responsible for protein synthesis?

• A. Nucleus
• B. Ribosome
• C. Golgi apparatus
• D. Mitochondria

Answer: (B)

The correct answer is that the ribosome is responsible for protein synthesis. Ribosomes play a crucial role in translating messenger RNA (mRNA) into polypeptide chains by linking together amino acids in the sequence specified by the mRNA. This process, known as translation, occurs either freely in the cytoplasm or on the surface of the endoplasmic reticulum, forming rough endoplasmic reticulum. The ribosome translates the genetic code carried by mRNA into functional proteins, which are essential for various cellular functions and activities.

Other structures mentioned have different primary roles. The nucleus is the control center of the cell, housing genetic material and coordinating cellular activities, including gene expression. The Golgi apparatus functions primarily in the modification, sorting, and packaging of proteins received from the endoplasmic reticulum for transport to various destinations. Mitochondria are known as the energy powerhouses of the cell, primarily involved in producing ATP through cellular respiration. Each of these organelles has specific functions that do not include direct involvement in the synthesis of proteins like ribosomes do.