d-aminolevulinic acid synthase:
- A. Requires pyridoxal phosphate for activity.
- B. Synthesis can be induced by phenobarbital
and some steroids.
- C. Is inhibited by heme.
Is inhibited by lead.
- A, B and C
A and C
B and D
All of the above
- A. Pyridoxal (vitamin B6) phosphate antagonists, such as the
anti-tuberculosis drug, isoniazide, can inhibit this enzyme.
- B. Phenobarbital is contraindicated for patients
with porphyria for this reason.
- C. This is a major physiological control.
- D. ALA dehydratase and ferrochelatase are
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