KROK 1 2020 – Question 58 · KROK (Medicine) · Biological Chemistry
One of the causes of pernicious anemia is the disturbed synthesis of transcorrin - Castle’s intrinsic factor - in the parietal cells of the stomach. What substance is called Castle’s extrinsic factor?
- A. Pyridoxine
- B. Riboflavin
- C. Cobalamin
- D. Biotin
- E. Folic acid
Hint
In the two-part Castle system one component comes with food and the other is made by gastric parietal cells, so ask which nutrient needs a stomach-derived carrier.
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