23.An enzyme is a catalyst for a specific reaction by
(A) decreasing ΔG
(B) decreasing ΔΗ
(C) decreasing ΔG‡(intermediate)
(D) decreasing S
(E) increasing the reaction rate

19. Which of the following is INCORRECT about the inactive state of the Ras protein? (A) Cell proliferation activation (B) Gene mutation leads to cancer development (C) Changes conformation when bound to regulatory molecules (D) GDP bound form (E) The G1 motif of the five G motifs binds to GDP

20. Which of the following types of resistance is not provided by the plasmid for its host? (A) Antibiotics resistance (B) Heat resistance (C) Toxic resistance (D) Phage infection (E) Heavy metals

複選題21. Which of the following chemical bonds are involved in the stabilization of two proteins in one complex? (A) H-bond (B) Ionic bond (C) Van der Waals (D) Salt bridge (E) Peptide bond

22.Allosteric control of O2 binding is present in hemoglobolin but not myoglobin. This is because hemoglobin protein has (A) Quaternary structure (B) Tertiary structure (C) Secondary structure (D) Changes in conformation of subunit after oxygen binding (E) Iron

複選題24. Which of the following amino acids have UV absorption (A) Glycine (B) Cysteine (C) Aspartic Acid (D) Tyrosine (E) Tryptophan

複選題25. Which of the following amino acids is basic in the physiological condition? (A) Aspartic acid (B) Asparagine (C) Tryptophan (D) Lysine (E) Arginine

複選題26.Choose the CORRECT statement describing peptide bond in a polypeptide (A) It has the resonance of π electrons in double bond. (B) It is in planar structure (C) It is freely rotate to give flexibility in stretching. (D) Two peptide bonds have free rotation next to each other. (E) A peptide bond formation involves the conjugation between –COOH and –NH2

複選題27. Which of the following gene transcripts of RNA polymerase II in eukaryotic cells? (A) 45S ribosomal RNA (B) Glyceraldehyde dehydrogenase mRNA (C) (D) U6 snRNA (E) β-actin mRNA

28. E. coli does not express β-galactosidase when its growth medium contains glucose, because (A) CAP is not activated for DNA binding to promote transcription initiation of β-Galactosidase gene. (B) Glucose stimulates the expression of lac repressor. (C) Lac repressor binds to the lac operator sequence. (D) Glucose interferes with lactose binding with the lac repressor. (E) Glucose binds to Lac operator

29. Which of the following restriction enzymes when used to completely digest an E. coli genomic DNA sample would generate DNA fragments in average size of 256 bp. (A) Not I: GC/GGCCGC (B) Hind III: A/AGCTT (C) Hpa II: C/CGG (D) Hpa I: GTT/AAC (E) Alul AG/CT