[Campbell Biology P.894] Cycloheximide is a drug that inhibits protein synthesis. Predict it... | Practice Question

Cycloheximide is a drug that inhibits protein synthesis. Predict its effect on the de-etiolation process in plants, based on the provided text.

  • A: Cycloheximide would enhance de-etiolation by preventing the synthesis of repressors.
  • B: Cycloheximide would inhibit de-etiolation, as new proteins essential for the process cannot be synthesized.
  • C: Cycloheximide would only affect post-translational modification, not transcriptional regulation.
  • D: Cycloheximide would have no significant effect because de-etiolation primarily relies on activating existing proteins.

Explanation

The text explains that de-etiolation involves both post-translational modification activating preexisting enzymes and transcriptional regulation increasing or decreasing the synthesis of mRNA encoding a specific enzyme, thus leading to new protein synthesis . If protein synthesis is inhibited by cycloheximide, the plant would be unable to produce the new proteins necessary for a complete de-etiolation response, thereby inhibiting the process.