TCA: 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 · TCA

Sample item

What molecule is regenerated at end of TCA cycle?

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

The answer and the reasoning

C. Oxaloacetate

This item reviews TCA; Oxaloacetate is the best answer because it directly matches the biochemical or pathological mechanism described.

Option by option

  • A. Acetyl-CoA

    Acetyl-CoA does not fit the stated mechanism.

  • B. Pyruvate

    Pyruvate is unsupported by the key finding.

  • C. Oxaloacetate (correct)

    Correct. Oxaloacetate fits the defining feature.

  • D. Lactate

    Lactate is plausible but not the best answer.

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, Oxaloacetate. This item reviews TCA; Oxaloacetate is the best answer because it directly matches the biochemical or pathological mechanism described.

Why is "Acetyl-CoA" not the answer?

Acetyl-CoA does not fit the stated mechanism.

Why is "Pyruvate" not the answer?

Pyruvate is unsupported by the key finding.

Why is "Lactate" not the answer?

Lactate is plausible but not the best answer.

What concept does this question test?

It tests TCA in Biochemistry. The correct option holds because: Correct. Oxaloacetate fits the defining feature.

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 TCA?

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.