E. coli is grown under the following conditions. Predict whether or not the lac
ID: 261901 • Letter: E
Question
E. coli is grown under the following conditions. Predict whether or not the lac operon will be expressed and why in terms of CAP and the Lac repressor. (3 points)
lac operon
Growth conditions expression (very low, low or high) Explanation
high glucose, high lactose
low glucose, high lactose
high cAMP, no lactose
1. A cell biologist found that two different proteins with largely different structures were translated from two different mRNAs. These mRNAs, however, were transcribed from the same template within the cell nucleus. How could you best account for this?
Explanation / Answer
High glucose high lactose - low as glucose is available cAMP is not made and won't be able to attach to CAP, expression will happen on basal level.
Low glucose, high lactose - High expression of lac operon as cAMP will be made and will attach to the CAP site and lactose will detach the lac repressor that is attached to the operator and rna polymerase will transcribe the genes.
High cAMP, no lactose - Very low because repressor is attached to the operator and must be removed by lactose in order to get the RNA polymerase to transcribe the genes.
1) Different type of mRNA can be made from same template strand by the mechanism called alternative splicing. In alternative splicing, different combinations of exons are joined together resulting in different mRNA and this will result in different proteins.
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.