General anatomy and histology: brown adipose tissue: practice question

A Anatomy 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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Anatomy · General anatomy and histology: brown adipose tissue

Sample item

A newborn keeps warm through non-shivering thermogenesis in multilocular fat rich in mitochondria. Which inner mitochondrial protein allows this by dissipating the proton gradient as heat?

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

The answer and the reasoning

A. Uncoupling protein 1

Brown adipose tissue contains many mitochondria and uncoupling protein 1 (thermogenin). It lets protons re-enter the matrix without driving ATP synthase, so the energy is released as heat. This is important in newborns.

Option by option

  • A. Uncoupling protein 1 (correct)

    Correct. It lets protons leak back across the inner membrane and releases heat.

  • B. ATP synthase

    It uses the proton gradient to make ATP, so it conserves energy rather than releasing heat.

  • C. Adenine nucleotide translocase

    It exchanges ATP and ADP across the membrane and does not generate heat.

  • D. Cytochrome c oxidase

    It is a respiratory chain complex that pumps protons, and does not dissipate the gradient.

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 Anatomy question

What is the answer to this Anatomy question?

The best answer is A, Uncoupling protein 1. Brown adipose tissue contains many mitochondria and uncoupling protein 1 (thermogenin).

Why is "ATP synthase" not the answer?

It uses the proton gradient to make ATP, so it conserves energy rather than releasing heat.

Why is "Adenine nucleotide translocase" not the answer?

It exchanges ATP and ADP across the membrane and does not generate heat.

Why is "Cytochrome c oxidase" not the answer?

It is a respiratory chain complex that pumps protons, and does not dissipate the gradient.

What concept does this question test?

It tests General anatomy and histology: brown adipose tissue in Anatomy. It lets protons re-enter the matrix without driving ATP synthase, so the energy is released as heat. This is important in newborns.

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 General anatomy and histology: brown adipose tissue?

Learn every nerve by its route, its muscles and what a lesion looks like at the bedside. That one habit answers a large share of questions. Then use the flashcards and the other Anatomy 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.