4. Excess alcohol consumption can lead to Wernicke-Korsaff syndrome due to the lack of the vitamin thiamine. Which of the following metabolic conversions cannot occur in the absence of thiamine?
(A) Pyruvate + CO₂ → oxaloacetate
(B) Pyruvate → acetyl-CoA + CO₂
(C) a-ketoglutarate → succinyl-CoA + CO₂
(D) Phosphoenolpyruvate + CO₂ → oxaloacetate
(E) B and C

複選題80. 下列哪些屬於單相感應電動機？ (A)電容啟動式電動機 (B)分激式電動機 (C)分相式電動機 (D)蔽極啟動式電動機。

1. What is the approximate mass of a protein containing 200 amino acids? (Assume there are no other protein modifications.) (A)20,000 (B) 11,000 (C) 22,000 (D) 222,000 (E) None of the above.

2. Which is not correct concerning the models that are accepted to describe cooperative binding? (A) In the sequential model, the binding of a ligand changes the conformation of the subunit to which it binds, which in turn induces a change in neighboring subunits. (B) All known allosteric proteins exhibit either the concerted or sequential model exclusive of the other. (C) Both models incorporate a low affinity T-state and a higher affinity R-state. (D) Both models explain the sigmoid-shaped binding curve. (E) In the concerted model, all molecules exist either in the T-state or the R-state.

3. What two properties of water are important for biological interactions? (A) the polarity of water (B) the density of water (C) the cohesive properties of water (D) A and C (E) B and C

5. The ultimate reductant in synthesis of deoxyribonucleotides is: (A)FADH2 (B) NADH (C) NADPH (D) quinine (E) none of the above

6. Tryptophan is a precursor for the neurotransmitter(s) (A)serotonin (B) norepinephrine (C) adenine (D) all of the above (E) none of the above

7. The carbon skeletons for amino acids are intermediates found in (A) glycolysis (B) citric acid cycle (C) pentose phosphate pathway (D) all of the above (E) none of the above.

8. Ketogenic amino acids are degraded to which of the following metabolites? (A) pyruvate (B) acetyl-CoA (C) acetoacetate (D) all of the above (E) B and C

9. Two-dimensional electrophoresis is a combination of what two techniques? (A)isoelectric focusing and affinity chromatography (B) ion-exchange chromatography and SDS-PAGE (C) affinity chromatography and SDS-PAGE (D) isoelectric focusing and SDS-PAGE (E) isoelectric focusing and ion-exchange chromatography

10. The use of synthetic peptides includes (A)use as antigens for making antibodies (B) drugs (C) "hooks" used in purification (D) all of the above (E) A and C