Question

which of these is the primary site of protein synthesis?
mitochondria
cytoplasm
nucleus
ribosomes

Explanation:

• Mitochondria are the power - houses of the cell, mainly involved in energy production (ATP synthesis).
• The cytoplasm is the fluid - like substance in the cell where many metabolic reactions occur, but not the primary site of protein synthesis.
• The nucleus is the control center of the cell, housing the genetic material (DNA). It is involved in transcription (making mRNA from DNA) but not the actual site of protein synthesis.
• Ribosomes are the organelles where translation (protein synthesis) occurs. mRNA is translated into a polypeptide chain (protein) at the ribosomes.

Answer:

Ribosomes.