Redox metabolism: 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 · Redox metabolism

Sample item

Why is NADPH production through the pentose phosphate pathway important in erythrocytes?

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

The answer and the reasoning

A. It maintains reduced glutathione against oxidative stress

Erythrocytes use NADPH to keep glutathione reduced, protecting haemoglobin and membrane lipids from oxidative injury; impaired generation, as in G6PD deficiency, predisposes to haemolysis under stress.

Option by option

  • A. It maintains reduced glutathione against oxidative stress (correct)

    Correct: NADPH supports glutathione-dependent antioxidant defense in red cells.

  • B. It creates urea for excretion

    Urea is synthesized mainly in the liver through the urea cycle.

  • C. It stores glycogen in the nucleus

    Glycogen is not stored in the nucleus.

  • D. It transports oxygen in plasma

    Oxygen is transported chiefly by haemoglobin rather than NADPH.

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.

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Questions about this Biochemistry question

What is the answer to this Biochemistry question?

The best answer is A, It maintains reduced glutathione against oxidative stress. Erythrocytes use NADPH to keep glutathione reduced, protecting haemoglobin and membrane lipids from oxidative injury; impaired generation, as in G6PD deficiency, predisposes to haemolysis under stress.

Why is "It creates urea for excretion" not the answer?

Urea is synthesized mainly in the liver through the urea cycle.

Why is "It stores glycogen in the nucleus" not the answer?

Glycogen is not stored in the nucleus.

Why is "It transports oxygen in plasma" not the answer?

Oxygen is transported chiefly by haemoglobin rather than NADPH.

What concept does this question test?

It tests Redox metabolism in Biochemistry. The correct option holds because: Correct: NADPH supports glutathione-dependent antioxidant defense in red cells.

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 Redox metabolism?

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.