Carbohydrate 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 · Carbohydrate metabolism

Sample item

Which organ normally contributes most to gluconeogenesis during an overnight fast?

ALiverBSkeletal muscleCErythrocytesDAdipose tissue

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

The answer and the reasoning

A. Liver

The liver maintains plasma glucose during fasting through glycogenolysis and gluconeogenesis; skeletal muscle lacks glucose-6-phosphatase and cannot release substantial free glucose into blood.

Option by option

A. Liver (correct)
Correct: the liver is the major gluconeogenic organ in routine fasting.
B. Skeletal muscle
Muscle uses its glycogen locally and cannot export free glucose efficiently.
C. Erythrocytes
Erythrocytes lack mitochondria and cannot perform gluconeogenesis.
D. Adipose tissue
Adipose tissue provides fatty acids and glycerol but is not the major gluconeogenic organ.

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 A, Liver. The liver maintains plasma glucose during fasting through glycogenolysis and gluconeogenesis; skeletal muscle lacks glucose-6-phosphatase and cannot release substantial free glucose into blood.

Why is "Skeletal muscle" not the answer?

Muscle uses its glycogen locally and cannot export free glucose efficiently.

Why is "Erythrocytes" not the answer?

Erythrocytes lack mitochondria and cannot perform gluconeogenesis.

Why is "Adipose tissue" not the answer?

Adipose tissue provides fatty acids and glycerol but is not the major gluconeogenic organ.

What concept does this question test?

It tests Carbohydrate metabolism in Biochemistry. The correct option holds because: Correct: the liver is the major gluconeogenic organ in routine fasting.

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 Carbohydrate 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.