23. Which of the following amino acids is the crucial precursor for the biosynthesis of melatonin?
(A) Phenylalanine
(B) Methionine
(C) Lysine
(D) Tryptophan

19. Aspirin is well-known as an inhibitor of_______.(A) lipoxygenase (B) hormone sensitive lipase (C) cyclooxygenase (D) fatty acid synthase (E) acetyl-CoA carboxylase

20. Which is not derived from arachidonic acid? (A) lipoxin (B) prostaglandin (C) thromboxane (D) leukotriene (E) prednisone

21. In fatty acid synthesis, acetyl group is shuttled out of mitochondria as: (A) pyruvate (B) oxaloacetate (C) α-ketoglutarate (D) glutamine (E) citrate

22. Which of the metabolites in the urea cycle is linked to the citric acid cycle? (A) Citrulline(B) Argininosuccinate (C) Arginine(D) Ornithine

24. Which is not an electron acceptor in the mitochondrial respiratory chain? (A) FMN(B) FAD(C) Fe3+(D) Cu2+ (E) Coenzyme A

25. Which is the active sugar in glycogen synthesis in animal? (A) CDP-glucose (B) GDP-glucose (C) UDP-glucose (D) Glucose 6-phosphate (E) Glucose 1-phosphate

26. Which of the following compounds is not a product of the enzymatic steps in the citric acid cycle? (A) Acetyl-CoA (B) -ketoglutarate (C) Succinate (D) Fumarate (E) Malate

27. Gout is caused by aberrant degradation of purine, leading to accumulation of uric acid. Allopurinol inhibits_______, leading to reduce the production of uric acid. (A) purine nucleoside phosphorylase (B) xanthine oxidase (C) nucleotidase (D) urease (E) hypoxanthine-guanine phosphoribosyltransferasse

28. Which of the following enzymes cannot catalyze the formation of a phosphodiester bond? (A) RNA polymerase (B) DNA polymerase (C) Ligase (D) Endonuclease (E) Reverse transcriptase

複選題29. Histones are found in eukaryotic cell nuclei that package and order the DNA into structural units called nucleosomes. They are usually rich in _______, and they interact with DNA via _______. (A) lysine and arginine; ionic bonds (B) glutamic acid and aspartic acid; hydrogen bonds (C) alanine and glycine; ionic bonds (D) lysine and arginine; hydrogen bonds (E) glutamic acid and aspartic acid; ionic bonds