Biomolecules and enzymes: advanced glycation end products: 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 · Biomolecules and enzymes: advanced glycation end products

Sample item

In a patient with long-standing poorly controlled diabetes, glucose attaches without enzymes to lysine residues of long-lived proteins such as collagen, and later rearrangements produce cross-links that stiffen vessel walls. What are these final products called?

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

The answer and the reasoning

B. Advanced glycation end products

Non-enzymatic glycation forms a Schiff base and then an Amadori product, as in HbA1c. Further irreversible rearrangement of these products gives advanced glycation end products, which cross-link collagen, bind the RAGE receptor and contribute to microvascular and macrovascular complications.

Option by option

  • A. Polyol pathway intermediates

    Polyol pathway intermediates such as sorbitol come from enzymatic reduction of glucose by aldose reductase, not from protein glycation.

  • B. Advanced glycation end products (correct)

    Correct. Advanced glycation end products form irreversibly from Amadori products and cross-link long-lived proteins.

  • C. Oxidised LDL particles

    Oxidised LDL arises from lipid oxidation in the arterial wall, not from the attachment of glucose to proteins.

  • D. N-linked glycoproteins

    N-linked glycoproteins are made enzymatically in the endoplasmic reticulum and Golgi, with a defined sugar chain.

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 B, Advanced glycation end products. Non-enzymatic glycation forms a Schiff base and then an Amadori product, as in HbA1c.

Why is "Polyol pathway intermediates" not the answer?

Polyol pathway intermediates such as sorbitol come from enzymatic reduction of glucose by aldose reductase, not from protein glycation.

Why is "Oxidised LDL particles" not the answer?

Oxidised LDL arises from lipid oxidation in the arterial wall, not from the attachment of glucose to proteins.

Why is "N-linked glycoproteins" not the answer?

N-linked glycoproteins are made enzymatically in the endoplasmic reticulum and Golgi, with a defined sugar chain.

What concept does this question test?

It tests Biomolecules and enzymes: advanced glycation end products in Biochemistry. Further irreversible rearrangement of these products gives advanced glycation end products, which cross-link collagen, bind the RAGE receptor and contribute to microvascular and macrovascular complications.

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 Biomolecules and enzymes: advanced glycation end products?

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.