You are studying a new strain of E. coli that can utilize the disaccharide melibiose very efficiently. You find that utilization depends on the enzyme melibiase, which is encoded by the gene Mel1. Mel1 is not expressed unless melibiose is present in the growth medium. You have isolated a mutation that causes constitutive melibiase activity, which you designate MelA–. P1 phage mapping experiments using a Tn5 insertion linked to Mel1 show that MelA– is not linked to Mel1. Moreover you find that when an amber suppressor is introduced into a MelA– mutant, normal melibiase regulation is restored. Classify the MelA– mutation on the basis of genetic properties,  make a proposal for the type of regulatory functions affected by the MelA– mutation?

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#Question id: 17279

#SCPH01 Biochemistry

Which of the following is relatively more stable to heat

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#Question id: 4161

#SCPH01 Biochemistry

The link between an activated amino acid and tRNA is an __ bond between the __ of the amino acid and a hydroxyl group of the tRNA.

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#Question id: 1018

#SCPH28 | Zoology

Diseases such as ulcers and cardiovascular disease

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#Question id: 4132

#SCPH01 Biochemistry

In E. coli, aminoacyl-tRNA synthetases:

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#Question id: 3667

#SCPH05 I Biotechnology

In an ______________ plasmid, replication occurs in two stages. In the first stage, the double stranded circular plasmid DNA replicates to form another double-stranded circular DNA and a single-stranded circular DNA, In the second stage, the complementary strand is synthesized on the single-stranded DNA to make another double-stranded DNA.