Lipid metabolism: lipoprotein lipase in fasting: 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 · Lipid metabolism: lipoprotein lipase in fasting

Sample item

In the fasting state, plasma triglyceride-rich lipoproteins are directed toward heart and skeletal muscle rather than adipose tissue. Which change in lipoprotein lipase activity underlies this redistribution?

AAdipose activity rises and cardiac activity fallsBAdipose activity falls and cardiac activity risesCBoth fall equally and plasma triglyceride clears slowlyDBoth rise equally in response to glucagon

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

The answer and the reasoning

B. Adipose activity falls and cardiac activity rises

Lipoprotein lipase in adipose tissue is induced by insulin, so its activity falls during fasting. In the heart, activity rises, which directs fatty acids from circulating lipoprotein triglyceride to the myocardium to be oxidised for energy while storage in fat is reduced.

Option by option

A. Adipose activity rises and cardiac activity falls
The reverse pattern occurs in the fed state, when insulin raises adipose LPL.
B. Adipose activity falls and cardiac activity rises (correct)
Correct. Fasting lowers adipose LPL and raises cardiac LPL, favouring oxidation over storage.
C. Both fall equally and plasma triglyceride clears slowly
The tissue-specific change is a redistribution, not an equal fall in both tissues.
D. Both rise equally in response to glucagon
Glucagon does not raise LPL in both tissues; insulin is the main inducer in adipose tissue.

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.

Questions about this Biochemistry question

What is the answer to this Biochemistry question?

The best answer is B, Adipose activity falls and cardiac activity rises. Lipoprotein lipase in adipose tissue is induced by insulin, so its activity falls during fasting.

Why is "Adipose activity rises and cardiac activity falls" not the answer?

The reverse pattern occurs in the fed state, when insulin raises adipose LPL.

Why is "Both fall equally and plasma triglyceride clears slowly" not the answer?

The tissue-specific change is a redistribution, not an equal fall in both tissues.

Why is "Both rise equally in response to glucagon" not the answer?

Glucagon does not raise LPL in both tissues; insulin is the main inducer in adipose tissue.

What concept does this question test?

It tests Lipid metabolism: lipoprotein lipase in fasting in Biochemistry. In the heart, activity rises, which directs fatty acids from circulating lipoprotein triglyceride to the myocardium to be oxidised for energy while storage in fat is reduced.

How hard is this question?

We tag it as a multi-step question: it asks you to combine more than one idea. 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 Lipid metabolism: lipoprotein lipase in fasting?

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.