What is the role of arabinose in the experiment?

What is the role of arabinose in the experiment?

• A. It acts as an inducer for the ara operon enabling rfp expression.
• B. It acts as a carbon source but not involved in gene expression.
• C. It inhibits expression of rfp.
• D. It binds ampicillin.

Answer: (A)

Arabinose acts as an inducer that turns on gene expression from the ara promoter. It binds to the regulatory protein AraC, causing a change that enables RNA polymerase to transcribe the downstream RFP gene, so RFP is produced when arabinose is present. In the absence of arabinose, AraC prevents transcription, keeping RFP off. That makes this choice the best because the experiment is designed around an inducible system, where arabinose signals the cell to express RFP. It is not simply a carbon source for metabolism, it does not inhibit expression, and it does not interact with ampicillin.

Arabinose acts as an inducer that turns on gene expression from the ara promoter. It binds to the regulatory protein AraC, causing a change that enables RNA polymerase to transcribe the downstream RFP gene, so RFP is produced when arabinose is present. In the absence of arabinose, AraC prevents transcription, keeping RFP off. That makes this choice the best because the experiment is designed around an inducible system, where arabinose signals the cell to express RFP. It is not simply a carbon source for metabolism, it does not inhibit expression, and it does not interact with ampicillin.