Classify the following examples of prokaryotic gene expression as positive or negative gene regulation. Positive gene...

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Classify the following examples of prokaryotic gene expression as positive or negative gene regulation. Positive gene regulation means the regulatory protein has a positive effect on transcription, negative gene regulation means the opposite. I am going to give you the answer to one of these, because we did not talk about this level of lac operon gene regulation in class: place "In the presence of lactose and low glucose, the lac operon..." in the "Positive gene regulation" box. Determine where to place the other choices on your own. Positive gene regulation Negative gene regulation In the absence of lactose, the lacR repressor protein binds the lac operon. If the sugar arabinose is present, an activator protein binds the promoter of the genes responsible for processing arabinose and induces their transcription. When excess tryptophan is present, a repressor protein binds the operator of the trp operon and prevents the operon from being transcribed. In the presence of lactose and low glucose, the lac operon is expressed 20-fold higher than in the absence of lactose. In the presence of iron, the dtxR repressor protein binds DNA, and the gene that encodes for the diphtheria toxin is not expressed. Mutations in which of the following lac operon genes or regions are cis-acting in their effect on the regulation of the operon? (Note: I will give you a diagram and labels for any detailed operon question on an exam. For now, please use the figures in your book.) laco lacl lacz lacP lacy Classify the following examples of prokaryotic gene expression as positive or negative gene regulation. Positive gene regulation means the regulatory protein has a positive effect on transcription, negative gene regulation means the opposite. I am going to give you the answer to one of these, because we did not talk about this level of lac operon gene regulation in class: place "In the presence of lactose and low glucose, the lac operon..." in the "Positive gene regulation" box. Determine where to place the other choices on your own. Positive gene regulation Negative gene regulation In the absence of lactose, the lacR repressor protein binds the lac operon. If the sugar arabinose is present, an activator protein binds the promoter of the genes responsible for processing arabinose and induces their transcription. When excess tryptophan is present, a repressor protein binds the operator of the trp operon and prevents the operon from being transcribed. In the presence of lactose and low glucose, the lac operon is expressed 20-fold higher than in the absence of lactose. In the presence of iron, the dtxR repressor protein binds DNA, and the gene that encodes for the diphtheria toxin is not expressed. Mutations in which of the following lac operon genes or regions are cis-acting in their effect on the regulation of the operon? (Note: I will give you a diagram and labels for any detailed operon question on an exam. For now, please use the figures in your book.) laco lacl lacz lacP lacy

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