33. What is the concentration of an adenine solution whose absorbance at 257=0.330? (ɛm = 15,100) Assume path length = 1.00 cm.
(A) 2.18×10^-6 M
(B) 2.18 × 10^-5 M
(C) 3.3 × 10^-6 M
(D) 3.3 × 10^-5 M
(E) 6.6 × 10^-4 M

複選題29. Which of the following amino acid residues are positively charged in buffer with pH 7: (A) Arginine (B) Aspartate (C) Phenylalanine (D) Lysine (E) Tryptophan

複選題30. What the following statements for enzyme is/are TURE: (A) Catalytic activity and substrate binding activity can not be separated (B) Catalytic function of an enzyme mostly relies on the charged group on the amino acid side chains (C) In Michaelis-Menten curve, same amount of enzyme with defects in substrate binding can never reach to the same Vmax as wild-type (D) The velocity (V) of catalysis of an enzyme is constant and it is independent of substrate concentration (E) Dissociation constant (Kd) can be used to represent the binding affinity between enzyme and substrate

複選題31.Regulation of transcription in mammalian cells (A) altering the spacing between promoter-proximal elements or enchancers and the TATA box has been shown to have more effect on transcription from some eukaryotic promoters. (B) some transcription factors can form heterodimers, and have less advantages to cells. (C) DNA-binding domain and activation domain can be in different protein subunits. (D) involves hormone receptors normally found in the nucleus. (E) as the number of initiation-complex components bound to the promoter increases, the gel migration of the DNA-protein complex will decrease.

複選題32.Structure and function of RNA in vivo and in vitro (A) has fewer hydroxy groups than DNA. (B) can fold back on itself to form double-helical regions with DNA. (C) is less susceptible than DNA to degradation at high pH. (D) like DNA, is a long, unbranched macromolecule consisting of nucleotides joined by 5'→ 3' phosphodiester bonds. (E) can act as a catalyst.

複選題34.A single amino acid changes in a protein may (A) eliminate all antigenicity (B) have no effect on antigenicity (C) make protein more stable. (D) produce cross-reacting material (E) change its subcellular localization

複選題35. Which of the following statement(s) is/are TURE? (A) Cloned cDNA can be translated in vitro to yield labeled proteins. (B) Suppressor mutations can identify genes encoding interacting proteins. (C) Transcription start sites can be mapped by S1 protection and primer extension. (D) DNA polymorphisms are used to map human mutations. (E) Nuclease-protection method can quantitate specific RNAs in a mixture and mapping them.

36. What is the cell density of a bacterial culture if plating 0.2 ml of a 105-fold dilution of the culture yields 45 colonies. (A) 4.5 × 106 (B) 9.0 × 106 (C) 2.25 × 107 (D) 4.5 × 107 (E) 9.0 × 107

複選題37. Which of the following statement(s) is/are TURE? (A) An entire genome can be cloned as fragments in a heterogeneous population of microbial cell or viruses that is called a cDNA library. (B) Single stranded nucleic acids with complementary of nucleotide sequence will find and hybridize to each other in solution. (C) Protein-coding regions of eukaryotic genes can be obtained by synthetizing genomic DNA from mRNA populations. (D) The variant phenotypes associated with organellar DNA variants are transmitted by cytoplasmic contact alone. (E) Mitochondria and chlroroplasts have their own unique linear DNA "chromosomes" distinct from nuclear DNA.

複選題38. Which of the following characteristic(s) is/are TURE for enhancer regions in eukaryotic DNA? (A) DNA Pol I binding sites (B) orientation and position dependent (C) promote transcription (D) bind transcription factors (E) promote better cloning efficiency

複選題39. Which of the following techniques CAN be used to check DNA binding proteins? (A) DNAase I sensitivity assay (B) Southern blot (C) Chromatin immunoprecipitation assay (D) Primer extension assay (E) Electrophoretic mobility shift assay