Pyruvate Dehydrogenase Complex MCQ Quiz | TCA & Bioenergetics

Welcome to this focused quiz on the Pyruvate Dehydrogenase (PDH) Complex, a crucial multi-enzyme structure linking glycolysis to the TCA cycle. This quiz is designed for MBBS students to test their understanding of the PDH complex’s structure, components (E1, E2, E3), cofactors, intricate regulatory mechanisms, and clinical significance. Covering everything from allosteric and covalent modification to conditions like Beriberi and arsenic poisoning, these 25 questions will challenge your knowledge. After submitting your answers, you’ll see your score and a detailed review of each question. You can also download a PDF of all questions with the correct answers for your revision. Good luck!

1. The Pyruvate Dehydrogenase Complex (PDC) catalyzes the conversion of pyruvate to which of the following key metabolic intermediates?

2. Which coenzyme is required for the E1 component (Pyruvate Dehydrogenase) of the PDC?

3. The E2 component of the PDC, Dihydrolipoyl transacetylase, utilizes which two coenzymes?

4. Dihydrolipoyl dehydrogenase (E3) is a component of PDC and also which other enzyme complex?

5. Arsenic poisoning primarily inhibits the PDH complex by binding to:

6. Which of the following is a potent allosteric inhibitor of the Pyruvate Dehydrogenase Complex?

7. The activity of the PDH complex is increased by the action of which enzyme?

8. High concentrations of ATP, NADH, and Acetyl-CoA will have what effect on PDH Kinase?

9. A deficiency of which vitamin would most directly impair the function of the Pyruvate Dehydrogenase Complex?

10. In skeletal muscle, PDH Phosphatase is strongly activated by which ion during contraction?

11. A genetic defect in the E1 subunit of PDC is a common cause of congenital lactic acidosis. This is because pyruvate is shunted to form lactate by which enzyme?

12. The overall reaction catalyzed by PDC is an example of:

13. Which of the five coenzymes required by PDC is NOT derived from a B vitamin?

14. Insulin signaling in adipose tissue leads to:

15. The “swinging arm” mechanism in the PDC involves which coenzyme transferring intermediates between the active sites of E1, E2, and E3?

16. The PDC is located in which subcellular compartment?

17. Which product of the PDC reaction provides direct feedback inhibition to the complex?

18. The disease Beriberi is caused by a severe deficiency of thiamine. Which symptom is directly related to impaired PDC function?

19. Phosphorylation of the E1 component of PDC by PDH kinase occurs on which amino acid residue?

20. What is the fate of the two electrons transferred to FAD on the E3 subunit?

21. A high NAD+/NADH ratio would have what effect on the PDC?

22. Which of the following conditions would favor the dephosphorylated (active) state of the PDC?

23. Leigh syndrome, a severe neurological disorder, can be caused by mutations in genes encoding which of the following?

24. The core of the PDC, to which E1 and E3 bind, is composed of which enzyme?

25. During starvation, increased fatty acid oxidation leads to high levels of Acetyl-CoA. This results in:

Author

  • G S Sachin Author Pharmacy Freak
    : Author

    G S Sachin is a Registered Pharmacist under the Pharmacy Act, 1948, and the founder of PharmacyFreak.com. He holds a Bachelor of Pharmacy degree from Rungta College of Pharmaceutical Science and Research and creates clear, accurate educational content on pharmacology, drug mechanisms of action, pharmacist learning, and GPAT exam preparation.

    Mail- Sachin@pharmacyfreak.com

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