Protein synthesis-inhibiting drugs, such as streptomycin, affect the action of the cell's ______.

• A. nucleus
• B. mitochondria
• C. ribosomes
• D. cell membrane

Answer: (C)

Verified step by step guidance

1. Understand that protein synthesis-inhibiting drugs target the cellular machinery responsible for making proteins.
2. Recall that the nucleus contains DNA and controls genetic information but does not directly synthesize proteins.
3. Recognize that mitochondria are involved in energy production, not protein synthesis.
4. Identify that the cell membrane controls the passage of substances in and out of the cell, but is not involved in protein synthesis.
5. Conclude that ribosomes are the cellular structures where proteins are synthesized, and thus are the target of drugs like streptomycin.