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MDCAT
Biology
2021

Biology · Bioenergetics

Work through this past-paper style MCQ, then read the full explanation. Practice more biology questions on mMCQ with adaptive practice and topic analytics.

Question

The respiratory chain electron carrier that directly binds oxygen is:

Options
  • A

    Cytochrome a

  • B

    Cytochrome a3

  • C

    Cytochrome c1

  • D

    Cytochrome b

Explanation

The respiratory chain electron carrier that directly binds oxygen is cytochrome a3. Cytochrome a3 is the final electron carrier in the electron transport chain, and it is located in complex IV. When electrons are transferred to cytochrome a3, they are oxidized and combine with oxygen to form water.

Cytochrome a is an electron carrier that is located in complex III, and it passes electrons to cytochrome a3.

The respiratory chain electron carrier that directly binds oxygen is cytochrome a3. Cytochrome a3 is the final electron carrier in the electron transport chain, and it is located in complex IV. When electrons are transferred to cytochrome a3, they are oxidized and combine with oxygen to form water.

Cytochrome c1 is an electron carrier that is located in complex III and complex IV, and it passes electrons between these complexes.

Cytochrome b is an electron carrier that is located in complex I and complex III, and it passes electrons between these complexes.

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Tagged under Biology · Bioenergetics · 2021