Oxidative phosphorylation: practice question

A Biochemistry question in the style of the NEET PG paper. Answer it first, then read why the right option is right and why each of the others is wrong.

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Biochemistry · Oxidative phosphorylation

Sample item

Which complex directly reduces oxygen to water?

Original practice item, not a recalled exam question. Nothing here is recorded.

The answer and the reasoning

C. Complex IV

This item reviews Oxidative phosphorylation; Complex IV is the best answer because it directly fits the mechanism or morphology described.

Option by option

  • A. Complex I

    Complex I does not match the key mechanism or pattern.

  • B. Complex III

    Complex III is not supported by the stated finding.

  • C. Complex IV (correct)

    Correct. Complex IV is supported by the defining finding.

  • D. Complex II

    Complex II is plausible but is not the best fit here.

Source note: Original NextPrep sample item — pending expert review. This item is original practice material awaiting independent expert review, so confirm important facts in a standard textbook.

More Biochemistry questions

Questions about this Biochemistry question

What is the answer to this Biochemistry question?

The best answer is C, Complex IV. This item reviews Oxidative phosphorylation; Complex IV is the best answer because it directly fits the mechanism or morphology described.

Why is "Complex I" not the answer?

Complex I does not match the key mechanism or pattern.

Why is "Complex III" not the answer?

Complex III is not supported by the stated finding.

Why is "Complex II" not the answer?

Complex II is plausible but is not the best fit here.

What concept does this question test?

It tests Oxidative phosphorylation in Biochemistry. The correct option holds because: Correct. Complex IV is supported by the defining finding.

How hard is this question?

We tag it as an application question: it asks you to use a fact on a patient or a finding. The tag is our own editorial judgement, not an official difficulty rating, so read the reason for every option, not only the answer.

How should I study Oxidative phosphorylation?

Build one table of enzyme deficiency, disease, inheritance and key finding, then revise it by spaced recall. Then use the flashcards and the other Biochemistry questions on this site to test what stuck.

Is this a real NEET PG question?

No. It is an original practice item (editorial status: sample, version 1). NextPrep does not publish recalled or leaked questions, and independent faculty review of this item has not been completed yet, so confirm important facts in a standard textbook.