The lac operon consists of three structural genes, lacZ, lacY and lacA that are transcribed as asingle polycistronic mRNA. You are given a new strain of Escherichia coli with the followinglac operon genotype:p+0°Z•Y*A +// P*O*Z*Y+ A-(i)Explain how the lac I gene affects gene expression.(ii)Explain the function of the lacP in the bacterial operon.(iii)Which part of the lac operon is cis-dominant? Explain.

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The lac operon consists of three structural genes, lacZ, lacY and lacA that are transcribed as a single polycistronic mRNA. You are given a new strain of Escherichia coli with the following lac operon genotype: P+OcZ-Y+A+// Explain how the lac I gene affects gene expression. Explain the function of the lacP in the bacterial operon. Which part of the lac operon is cis-dominant? Explain. P+O+Z+Y*A* (i) (ii) (iii)

The lac operon consists of three structural genes, lacZ, lacY and lacA that are transcribed as a single polycistronic mRNA. You are given a new strain of Escherichia coli with the following lac operon genotype: P+OcZ-Y+A+// Explain how the lac I gene affects gene expression. Explain the function of the lacP in the bacterial operon. Which part of the lac operon is cis-dominant? Explain. P+O+Z+YA (i) (ii) (iii)

Biology (MindTap Course List)

11th Edition

ISBN:9781337392938

Author:Eldra Solomon, Charles Martin, Diana W. Martin, Linda R. Berg

Publisher:Eldra Solomon, Charles Martin, Diana W. Martin, Linda R. Berg

Chapter14: Gene Regulation

Section: Chapter Questions

Problem 11TYU

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The lac operon consists of regulatory regions such as the promoter as well as the structural genes lacZ, lacY, and lacA, which code for proteins involved in lactose metabolism. What would be the outcome of a mutation in lacA?
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. a. How many ribosomes are required (at a minimum)for the translation of trpE and trpC from a singletranscript of the trp operon?b. How would you expect deletion of the two tryptophan codons in the RNA leader to affect theexpression of the trpE and trpC genes?
If glucose levels in the cell are high and lactose is available from the environment, what is the status of transcription of the lac operon genes? Explain your answer from both an evolutionary perspective and in terms of negative and positive regulation of the operon?
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