Arsenic poisoning can lead to organ failure and death. Though arsenic can inhibit or interfere with a number of cellular enzymes, arsenic poisoning is thought to be mainly due to indirect inhibition of enzymes involved in both pyruvate oxidation and the Krebs cycle. As a result, this compound must be able to enter which cellular compartment?

Question

A.  The cytoplasm
B.  The nucleus
C.  The intermembrane space of the mitochondria
D.  The mitochondrial matrix
E.  The endoplasmic reticulum

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 pyruvate oxidation and the Krebs cycle? What other information is related to the question?

  Choose Answer
  Do you have all necessary information to determine where arsenic poisoning would have its greatest impact within the cell?
 

Answer 1

D.  The mitochondrial matrix

Clarify Question
What is the key concept addressed by the question?
        · The question asks you to determine which cellular compartments would be involved with arsenic poisoning, which inhibits pyruvate oxidation and the Krebs cycle.
What type of thinking is required?
        · You are being asked to use what you know about pyruvate oxidation and the Krebs cycle, and apply this information to determine where arsenic poisoning would occur within the cell.

  Gather Content
  What do you already know about pyruvate oxidation and the Krebs cycle? What other information is related to the question?
        · Recall that cellular respiration involves four stages; glycolysis, pyruvate oxidation, the Krebs cycle, and the electron transport chain. Remember also that glycolysis occurs in the cytoplasm, and the products of glycolysis can be metabolized under either aerobic or anaerobic conditions. If you assume aerobic conditions, then pyruvate oxidation and the Krebs cycle will be used. Where do pyruvate oxidation and the Krebs cycle physically occur within cells?

  Choose Answer
  Do you have all necessary information to determine where arsenic poisoning would have its greatest impact within the cell?
        · As we discussed earlier, glycolysis occurs in the cytoplasm, and its products must be imported into the mitochondria to participate in pyruvate oxidation and the Krebs cycle, particularly when aerobic conditions exist.
        · Recall mitochondria are divided into several spaces which include.