Many of the antiviral drugs currently used to treat HIV/AIDS also interfere with an enzyme that helps mitochondria multiply. Treatment can therefore result in a decrease in the number of mitochondria found in certain tissues. Given this information, what might you expect to see in patients treated with antiviral drugs?

Question

A.  An increase in oxidative phosphorylation
B.  An increase in phosphofructokinase activity
C.  An increase in NADH dehydrogenase activity
D.  An increase in lactic acid levels

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 which cellular respiration processes occur in mitochondria? How would a reduction in mitochondria affect the ability of the cell to harvest energy? What other information is related to the question?

  Choose Answer   Do you have all necessary information to determine the outcome on respiration from taking antiviral drugs?

  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

D.  An increase in lactic acid levels

Clarify Question
What is the key concept addressed by the question?
        · The question asks you to determine what might happen in patients treated with antiviral drugs.
What type of thinking is required?
        · You are being asked to dissect, or analyze, the possible outcomes of antiviral drug treatment.   Gather Content
  What do you already know about which cellular respiration processes occur in mitochondria? How would a reduction in mitochondria affect the ability of the cell to harvest energy? What other information is related to the question?
        · Remember that cellular respiration is comprised of glycolysis, pyruvate oxidation, the Krebs cycle and electron transport. With the exception of glycolysis, all of these processes are related to aerobic respiration, which occurs inside the mitochondria.
        · If you follow the line of logic, what possible options is a cell left with if it cannot perform pyruvate oxidation, the Krebs cycle, or electron transport?

  Choose Answer   Do you have all necessary information to determine the outcome on respiration from taking antiviral drugs?
        · Let’s examine each answer in order to determine the correct one. We know that oxidative phosphorylation occurs during the electron transport chain and results from aerobic conditions. Considering that the electron transport chain is physically located inside the inner mitochondrial membrane, if the number of mitochondria decreases, so does the ability to conduct oxidative phosphorylation. That can’t be the right answer.
        · Phosphofructokinase is an enzyme that operates during glycolysis. Even though glycolysis doesn’t involve aerobic conditions, the question indicates that there would be an increase in phosphofructokinase activity. That typically happens when you need to ramp up ATP production, and since there are no mitochondria present due to the antiviral drugs, phosphofructokinase activity is more likely to go down. Likewise, NADH dehydrogenase activity is likely to go down for the same reasons described above.
        · By process of elimination, that leaves an increase in lactic acid levels. But to make sure that is the correct response let’s examine it further. If you have no mitochondria, aerobic respiration is not possible. Cells still need energy, and so how will they obtain it? Using the same mechanism that is required when cells have no oxygen but still have mitochondria present: lactic acid fermentation.

  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 the likely outcome for energy metabolism in patients who take antiviral drugs.         · If you got the correct answer, nice job! If you got an incorrect answer, were you able to associate the stages of cellular respiration with mitochondrial anatomy? Were you able to eliminate pyruvate oxidation, the Krebs cycle, and the electron transport chain as possible options because no mitochondria were present? Were you able to infer that the inability of cells exposed to antiviral drugs to aerobically harvest energy would necessitate anaerobic energy harvesting processes like lactic acid fermentation?