A biochemist wants to control the initial substrate-level phosphorylation that occurs in the tracheal cells of grasshoppers once glucose has crossed the plasma membrane. He has access to the following inhibitors: Rotenone - an electron transport chain inhibitor, Oligomycin - an ATP synthase inhibitor, and TLN-232, an inhibitor of glycolysis. Which inhibitor should he use to slow down initial substrate-level phosphorylation that occurs once glucose has crossed the plasma membrane?

Question

A.  Rotenone
B.  Oligomycin
C.  TLN-232
D.  None of these inhibitors would be effective in preventing substrate-level phosphorylation

Clarify Question
What is the key concept addressed by the question?
What type of thinking is required?

  Gather Content
  What do you already know about substrate-level phosphorylation during cellular respiration? What other information is related to the question?

  Choose Answer
Do you have all the information needed to determine which inhibitor would have the biggest impact on substrate-level phosphorylation?

  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

C.  TLN-232

Clarify Question
What is the key concept addressed by the question?
        · The question asks you to determine which chemical inhibitor would slow down initial substrate-level phosphorylation.
What type of thinking is required?
        · You are being asked to dissect, or analyze, the effects of each inhibitor on initial substrate-level phosphorylation once glucose has been imported into the cell.

  Gather Content
  What do you already know about substrate-level phosphorylation during cellular respiration? What other information is related to the question?
        · Recall that cellular respiration can produce ATP using two mechanisms; one that uses substrate-level phosphorylation and one that uses oxidative phosphorylation. Remember, oxidative phosphorylation provides the vast majority of ATP that a cell needs, provided oxygen is present.
        · Each of the three chemicals listed inhibits a different stage of cellular respiration. Which chemical would interfere most with initial substrate-level phosphorylation that could potentially occur right after glucose enters the cell?

  Choose Answer
Do you have all the information needed to determine which inhibitor would have the biggest impact on substrate-level phosphorylation?
        · The key to answering this question correctly is to realize when substrate-level phosphorylation occurs during cellular respiration, and more specifically when substrate-level phosphorylation first occurs after glucose enters the cell.
        · Remember that substrate-level phosphorylation occurs during glycolysis and the Krebs cycle. Since the question indicates that the inhibitor should slow initial substrate-level phosphorylation, that means the inhibitor should restrict ATP production during glycolysis.
        · Of the listed chemicals, TLN-232 is the only inhibitor to restrict glycolysis, and is therefore 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?
        · Answering this question correctly depended on your ability to analyze which inhibitor a biochemist should choose in order to slow down initial substrate-level phosphorylation.
        · If you got the correct answer, good thinking! If you got an incorrect answer, were you able to remember when during cellular respiration substrate-level phosphorylation occurs? Were you able to figure out that the substrate-level phosphorylation that would occur most following import of glucose would be during glycolysis? Were you able to use that information to choose TLH-232 from the list of inhibitors?