In a metabolic pathway A → B → C → D, an inhibitor stops the enzyme that converts B to C. Which substances are most likely to accumulate or fall?
Answer and explanation
Correct answer: D. B builds up while C and D fall
- Step 1: The step B → C is blocked.
- Step 2: B is made but not used, so it builds up; C and D are not made, so they fall.
Answer
B builds up while C and D fall.
Why not the others: A falls and B falls as the pathway shuts down: the blocked step is after B. C accumulates and D falls: C is made after the blocked step. D accumulates and A falls: D is made later.
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