An organism grown in a high nutrient liquid broth to high turbidity always appears to produce a blue pigment and even when a large inoculum is transferred to a nutrient rich agar plate it appears blue.
When the researcher noticed it never appears blue when very small colonies were grown in low nutrient agar plates. What is the most plausible conclusion?
A) Large populations enabled the differentiation of a subpopulation of cells that created the blue pigment.
B) Only high nutrient conditions provide enough energy for cells to produce this secondary metabolite that appears blue.
C) The blue pigment production is linked to quorum sensing.
D) The strong gradient from very high to low nutrient bioavailability induces production of the blue metabolite.
Which of the following IS a characteristic of an isoenzyme?
A) More than one enzyme is regulated by the same mechanism.
B) The same reaction can be catalyzed by multiple enzyme variants.
C) Multiple binding sites on the same enzyme enable multiple regulation mechanisms.
D) More than one gene makes the same enzyme.
Attenuation is a type of regulation that can control
A) allosteric enzyme activity.
B) transcriptional activity exclusively.
C) translational activity exclusively.
D) both transcriptional and translational activity.
Post-translational regulation of an enzyme's activity, such as glutamine synthetase, can be finely controlled at varied levels due to
A) the varied strengths metabolite-regulating compounds can have with the enzyme such as hydrogen bonding, covalent bonding, and van der Waals attractions.
B) having multiple independently functional subunits.
C) the structural strength enzymes have once properly folded compared to short-lived and easily degradable transcripts during translational regulation.
D) weak chemical modifications of the enzyme rather than harsh protein-protein or protein-DNA interactions.
When the nontemplate strand of a gene is transcribed into RNA, what is likely to result?
A) A complementary sRNA will bind to it and form a functional ribozyme with secondary structure.
B) It will complementary bind to the gene sequence, form a hairpin loop, and transcriptionally repress the gene.
C) The complementary mRNA also transcribed from the template strand will bind to it and halt its translation.
D) A global regulator will identify this as a stress, respond by inducing ribonuclease production, and it will degraded.
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