Do these experiments suggest that the arabinose operon is negatively or positively controlled? Explain your reasoning. Ellis Engelsberg and his colleagues examined the regulation of genestaking part in the metabolism of arabinose, a sugar (E. Engelsberg et al.1965. Journal of Bacteriology 90:946-957). Four structural genesencode enzymes that help metabolize arabinose (genes A, B, D, and E).An additional sequence C is linked to genes A, B, and D. These are inthe order D- A- B- C. Gene E is distant from the other genes. Engelsbergand his colleagues isolated mutations at the C sequence that affected theexpression of structural genes A, B, D, and E. In one set of experiments,they created various genotypes at A and C and determined whetherarabinose isomerase (the enzyme encoded by gene A) was produced inthe presence or absence of arabinose (the substrate of arabinoseisomerase) by cells with these genotypes. Results from this experimentare shown in the following table, where a plus sign (+) indicates that thearabinose isomerase was synthesized and a minus sign (-) indicates thatthe enzyme was not synthesized.ArabinoseArabirGenotypeabsentprese1. C* A*2. C A*3. C A*/C*4. CA/CA*

Name: Do these experiments suggest that the arabinose operon is negatively o
Uploaded: 2024-03-20T06:42:41.000Z
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Description: Do these experiments suggest that the arabinose operon is negatively or positively controlled? Explain your reasoning. Ellis Engelsberg and his colleagues examined the regulation of genestaking part in the metabolism of arabinose, a sugar (E. Engelsb