Reactive oxygen species: chronic granulomatous disease: practice question

The best answer is B, NADPH oxidase. Chronic granulomatous disease results from NADPH oxidase deficiency, preventing superoxide generation in phagocytes.

Glucose-6-phosphatase deficiency causes von Gierke disease.

Catalase is produced by microbes and host tissues, not the defective enzyme here.

Myeloperoxidase deficiency is usually milder and leaves superoxide generation intact.

It tests Reactive oxygen species: chronic granulomatous disease in Biochemistry. Catalase-positive organisms can survive because they do not provide sufficient hydrogen peroxide for killing.

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.

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.

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.