Question

o E. coli, the bacteria stop producing full-length mRNAs and instead accumulate short transcripts of 8-10 nucleotides in length. Which of the following steps in transcription is most likely affected by the drug? You work for a pharmaceutical company and discover a chemical compound with antibiotic properties. When this chemical is added to E. coli, the bacteria stop producing full-length mRNAs and instead accumulate short transcripts of 8-10 nucleotides in length. Which of the following steps in transcription is most likely affected by the drug? Elongation rate of the core polymerase Formation of the open complex Binding to the promoter Promoter clearance Rho-dependent termination

Answer 1

Answer:

The correct answer to the question: Which of the following steps in transcription is most likely affected? Would be: Formation of the open complex.

Explanation:

Depending on the type of bacteria, and the different structures that form the cell, antibiotics of different kinds will seek these structures to either inhibit the cell from performing its normal activities and reproducing, or doing that plus killing it. Of the second kind, called bactericidals, like Rifamycin drugs, these accomplish their purpose precisely by inhibiting steps in the DNA to RNA transcription that will result in the production of erroneous mRNA strands, and therefore, faulty proteins. When these steps are stopped, the bacteria is unable to protect itself, or repair itself, and while the process continues, the antibiotic, in high levels, starts to also eliminate the bacterial cell. Specifically, according to research done, medication like Rifamycin will stop the transcription of DNA into RNA by binding to an RNA transcribing enzyme that is located in the channel formed by the polymerase-DNA complex. In this way, nucleotides that should be added to the mRNA chain are not added and the result that comes out will be really short chains that cannot be translated later into protein.