As a microbiologist you have been asked to investigate the regulation of a novel gene in a bacterial species. Given what is known about bacteria, the logical place to begin your investigation is

Question

A.  transcriptional regulation.
B.  translational regulation.
C.  alternative splicing regulation.
D.  regulation by enhancer elements.
E.  regulation by general transcription factors.

Clarify Question
· What is the key concept addressed by the question?
· What type of thinking is required?
· What key words does the question contain and what do they mean?

Gather Content
· What do you already know about gene regulation in bacteria?

Consider Possibilities · Consider the different answer options. Which can you rule out?

Choose Answer
· Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?

Reflect on Process · Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?

Answer 1

A.  transcriptional regulation.

Clarify Question
· What is the key concept addressed by the question?
        o This question addresses gene regulation in bacteria.
· What type of thinking is required?
        o This question is asking you to take what you already know and apply it to this unfamiliar situation.
· What key words does the question contain and what do they mean?
        o Regulation of a gene refers to the control of its expression.
        o A novel gene is a new gene – that is, one that has not been well-studied or understood.
        o Bacteria are prokaryotes like E. coli or Salmonella. Their gene regulation is similar to eukaryotes, but has distinct features.

Gather Content
· What do you already know about gene regulation in bacteria?
        o Gene regulation in bacteria is similar to that of eukaryotes.
        o However, bacteria do not have a nucleus, therefore there is less separation between transcription and translation.
        o Because of this, bacteria tend to rely on transcriptional regulation more than translational or post-translational regulation.

Consider Possibilities · Consider the different answer options. Which can you rule out?
        o Is a prokaryotic gene likely to use alternative splicing regulation? No, prokaryotic genes don’t have introns, and don’t have splicing machinery.
        o Is a prokaryotic gene likely to use regulation by enhancer elements? No, prokaryotic genes don’t have distant enhancers like eukaryotic genes do.
        o Is a prokaryotic gene likely to use regulation by general transcription factors? No, this term is used for eukaryotes to differentiate the basal transcriptional machinery from more specific transcriptional regulatory proteins. Moreover, the general transcription factors do not play an important role in regulation.

Choose Answer
· Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?
        o Is a prokaryotic gene likely to use translational regulation? No. Since bacteria lack a nuclear membrane, transcription and translation are coupled.
        o Thus it is important that they regulate gene expression at the transcriptional level.
        o Transcriptional regulation is the most common mode of gene regulation in bacteria.

Reflect on Process · Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?
        o This question asked about the most common type of regulation in bacteria.
        o The question required you to take what you already know and apply it to this unfamiliar situation.
        o Did you recognize that transcriptional regulation is by far the most common type of regulation in bacteria?
        o Did you remember that bacteria lack splicing and lack enhancers?