Question

fill the blank

Cadbury chocolate eggs contain a highly addictive fictional (or is it??) sugar we'll call "cadburiose." Sawy gut microbes have evolved a novel operon to control expression of an enzyme necessary for cadburiose digestion (it is broken down into glucose). Your job is to deduce whether this operon is inducible or repressible, and whether the gene regulation is positive or negative. You test for alterations of gene expression by looking first at whether (and how much) mRNA for the enzyme is produced: O for none, + for baseline levels, and +++ for increased transcription. Secondly, you ascertain whether the protein enzyme produced from the structural gene is active or not. Bacterial genotype Conditions: standard growth medium plus: Cadbury eggs arabinose (another carbon Glucose (product) as (precursor) as sole source) sole carbon source carbon source Is enzyme active? Yes +++ WT A- 0 B- 0 +++ 0 +++ +++ Yes No D- yes +++ 0 +++ O Next, you perform some experiments in which you add additional bacterial chromosome pieces via F' plasmids, creating partial diploids. In the chart you are measuring enzyme activity only. Bacterial genotype A+B-C+D+E+ A+B+C+D-E+ A-B+C+D+E+ +B+C+D+E- | Conditions: standard growth medium plus: F' plasmid genotype | arabinose (another Cadbury eggs | Glucose carbon source) A+B+C-D+E+ +++ +++ + A+B+C-D+E+ +++ | 0 A+B+C+D+E+ +++ A+B+C+D+E+ 0 1 0 1 0 0 0 0 A How is this operon regulated? Glucose cadburvase expression by an). (induces/represses) _adding/removing) (activator/repressor) Cadbury eggs (induce/repress) cadburvase expression by. a(n) _ _adding/removing) (activator/repressor)

Answer 1

How is this operon regulated?

Answer

Represses Glucose cadburyase expression by Removing all Repressor (induces/represses) _adding/removing) (activator/repressor) Cadbury eggs Induce (induce/repress) - cadburvase expression by Adding a(n) Activator _adding/removing) (activator/repressor)

Which letters represent the following mutations? (Write "none" if there is no mutation in this protein/DNA sequence.) promoter none structural gene S syrerrepressor repressor (null)! or operator O or O Activator (null None superactivater_none activator binding site_None

Bacterial genotype F plasmid genotype Conditions: standard growth medium plus: arabinose Cadbury eggs Glucose (another carbon (precursor) source) A-B-C+D+ A+B+C-D- +++ A+B-C+D- A+B+C-D- + + + +++ A+B+C-D- A-B+C+D+ +++