Streptomycin is an antibiotic that interferes with the function of the 30S subunit of the prokaryotic ribosome. What is the consequence of treating a bacteria with streptomycin?

Question

A.  Impaired oxygen synthesis
B.  Impaired protein synthesis
C.  Impaired DNA synthesis
D.  Impaired ATP synthesis

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 know about the ribosome? How does it relate to the question?

Consider Possibilities
· What other information is related to the question? Which information is most useful?

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

B.  Impaired protein synthesis

Clarify Question
· What is the key concept addressed by the question?
        o The question asks about the function of the ribosome.
· What type of thinking is required?
        o You are being asked to apply your knowledge of the function of a ribosome to explain what would happen to a cell if this function were inhibited.
· What key words does the question contain and what do they mean?
        o 30S subunit of the prokaryotic ribosome – prokaryotes (bacteria) have ribosomes with two halves, the smaller 30S subunit and a larger 50S subunit.  The “S” is a measure of size based on how the ribosome sediments in a centrifuge.
        o Streptomycin – this is an antibiotic that blocks the function of the 30S subunit.  Antibiotics are used to kill bacteria.

Gather Content
· What do you know about the ribosome? How does it relate to the question?
        o Because streptomycin inhibits the 30S subunit of the ribosome, the ribosome will no longer be able to function properly.  The function of the ribosome is to synthesize proteins from a messenger RNA in translation.

Consider Possibilities
· What other information is related to the question? Which information is most useful?
        o The ribosome is not directly involved in oxygen, DNA, or ATP production in a cell.

Choose Answer
· Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?
        o The best answer is that inhibition of the 30S subunit of a ribosome by streptomycin will block translation of a mRNA and thus impair protein synthesis.  If a bacteria cannot make new proteins then it will not be able to divide, and will eventually die.

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 you to apply your knowledge of the function of a ribosome to explain how streptomycin would work as an antibiotic. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you recognize that because the 30S subunit was part of the ribosome, if it was inhibited then the ribosome would be inhibited?  Did you remember that the ribosome is involved in protein synthesis, so if the ribosome was inhibited protein synthesis would be impaired?