Cytochromes contain a heme group similar to that in hemoglobin. The iron atom (Fe) in the center of the group can be oxidized and reduced. If someone was suffering from iron deficiency anemia, what stage of cellular respiration would be most affected?

Question

A.  Glycolysis
B.  The Krebs cycle
C.  The electron transport chain
D.  Fermentation

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 redox reactions and when they take place during cellular respiration? What other information is related to the question?

  Choose Answer Do you have all the information needed to determine which stage of cellular respiration would be most affected by an iron deficiency?

  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.  The electron transport chain

Clarify Question
What is the key concept addressed by the question?
        · The question asks you to determine the stage of cellular respiration that would be most affected by iron deficiency anemia.
What type of thinking is required?
        · You are being asked to break down, or analyze, the options to determine the likely stage most affected by iron deficiency anemia.

  Gather Content
  What do you already know about redox reactions and when they take place during cellular respiration? What other information is related to the question?
        · You know that the stages of cellular respiration include glycolysis, pyruvate oxidation, the Krebs cycle, and electron transport. Under anaerobic conditions fermentation can also occur.
        · The question indicates that cytochromes that are similar to hemoglobin and can participate in oxidation and reduction reactions would be affected if an individual was deficient in iron and developed anemia. Essentially what this means is iron deficiency will reduce the ability of the cell to conduct redox reactions. During which stage of cellular respiration do most redox reactions occur?

  Choose Answer Do you have all the information needed to determine which stage of cellular respiration would be most affected by an iron deficiency?
        · Determining the right answer for this question is relatively straightforward. Let’s see if we can eliminate some options right off the bat. Certainly oxidation and reduction reactions happen during glycolysis, but none of them involve anything resembling cytochromes. That answer seems less likely.
        · Similarly, the Krebs cycle also contains redox reactions, but again no cytochromes. The same would hold true for fermentation; the absence of cytochromes makes these answers less likely to be correct.
        · That leaves the electron transport chain as a possible option, let’s see why it might or might not make sense as the correct answer. We know that redox reactions occur during the electron transport chain; what types of molecules help facilitate those redox reactions? In fact, it is cytochromes that participate in the redox reactions. Therefore, the stage of cellular respiration that would be most affected in someone suffering from iron deficiency anemia would be the electron transport chain.

  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 each option to determine which stage of cellular respiration would be most affected by someone suffering from iron deficiency anemia.
        · If you got the correct answer, nice job! If you got an incorrect answer, did you remember which stages of cellular respiration use redox reactions? Were you able to distinguish this from those that use cytochromes? Were you able to infer that the electron transport chain would be most affected in individuals suffering from iron deficiency anemia?