BCH 403 - Cumulative Final Exam Questions With Verified Answers

BCH 403 - Cumulative Final Exam Questions With Verified Answers A biochemical technique that can be used to identify all areas of DNA bound by histones is called: A. DNA-seq. B. ChIP-seq. C. DNase-seq. D. RNA-seq. E. Proteomics. - Answer-B. ChIP-seq /.A company has developed an effective inhibitor for an enzyme. The structure of the inhibitor does not resemble the substrate of the reaction. Which of the following is also likely to be true upon addition of the inhibitor? A. The final value of 1/Vmax has changed. B. The apparent Km has decreased. C. At [S] Km, the final Vmax will be the same with and without the inhibitor. D. The inhibitor is competitive with respect to substrate binding. - Answer-A. The final value of 1/Vmax has changed. /.A kinetics experiment reveals that a Michaelis constant (Km) of an enzyme for its substrate is equal to 7 μM. What can you safely conclude regarding the behavior of the enzyme? A. At 5 μM, the reaction is second order with respect to the enzyme. B. At 7 μM, the reaction is zero order with respect to substrate. C. The reaction Vmax occurs at greater than 7 μM substrate concentration. D. The reaction is already operating at Vmax. E. All of the answers are true. - Answer-C. The reaction Vmax occurs at greater than 7 μM substrate concentration. /.A membrane is compose of fatty acid tails that have the designation 16:2. Addition of which of the following fatty acids will increase the Tm of the membrane? A. 14:2 B. 18:2 C. 16:3 D. 16:4 - Answer-B. 18:2 /.A polypeptide that is made of 30 amino acids is cleaved by addition of trypsin into 5 different fragments. You want to remove one cleavage site. Which amino acid substitution will let you do this? A. Alanine to aspartate B. Asparagine to phenylalanine C. Tyrosine to glycine D. Lysine to asparagine E. Arginine to lysine - Answer-D. Lysine to asparagine /.A protein that binds a ligand is found to have a hill coefficient of 1.5. Which of the following is TRUE regarding its cooperativity? A. It cannot bind more than 1.5 molecules of ligand at once. B. Binding of the first molecule of ligand increases binding for the second molecule. C. Binding of the second molecule of ligand causes the first molecule to release. D. The protein displays negative cooperativity. E. The binding curve will be hyperbolic. - Answer-B. Binding of the first molecule of ligand increases binding for the second molecule. /.A reaction with a ΔG equal to zero can best be described as: A. A system where the reactants and products are equal. B. A system that has reached an equilibrium. C. A system that requires ATP as a thermodynamic coupler in order to reach equilibrium. D. A system where the change in entropy is the principle driving force. E. A system where the change in enthalpy is the principle driving force. - Answer-B. A system that has reached an equilibrium. /.Abortive initiation in prokaryotic transcription can be described as: A. Unwanted transcription B. A failed attempt of the RNA polymerase to escape the promoter C. A premature release of sigma (σ) subunit D. Failure to phosphorylate and activate RNA polymerase E. Unloading of the RNA polymerase off of the DNA template by a repressor - Answer-B. A failed attempt of the RNA polymerase to escape the promoter /.Acetyl-CoA carboxylase is inactivated in the presence of: A. Citrate B. Insulin C. Glucagon D. Malonyl-CoA E. Acetyl-CoA - Answer-C. Glucagon /.Adenine nucleotide translocase: A. Transports ATP out of the mitochondria while transporting ADP into the mitochondria B. Transports inorganic phosphate (Pi) into the mitochondria at the cost of two H+ C. Transports inorganic phosphate (Pi) out of the mitochondria matrix D. Transports H+ into the mitochondria matrix E. Transports electrons from cytosolic NADH into the mitochondria - Answer-A. Transports ATP out of the mitochondria while transporting ADP into the mitochondria /.All mutations that are directly involved in the development of cancer are called: A. Driver mutations. B. Passenger mutations. C. Oncogenes. D. Tumor suppressors. E. Sporadic cancers. - Answer-A. Driver mutations /.All of the following can be used as a precursor for gluconeogenesis, except: A. Lactate B. Alanine C. Glutamine D. Glycerol E. Lysine - Answer-E. Lysine /.Aminoacyl-tRNA synthetase: A. Loads aminoacyl-tRNAs into the A-site of the ribosome. B. Catalyzes the ATP-dependent addition of an amino acid onto the corresponding tRNA. C. Recharges elongation factor eEF-1α in eukaryotes (EF-Tu in prokaryotes). D. Synthesizes tRNA. E. Catalyzes the formation of a peptide bond - Answer-B. Catalyzes the ATP-dependent addition of an amino acid onto the corresponding tRNA /.An enzyme that weakly binds substrate will have a: A. low Km B. low Kcat/Km C. high Km D. low turnover number E. low Vmax - Answer-C. high Km /.DNA helicase: A. is part of the DNA polymerase. B. relieves supercoils caused by topoisomerase. C. undergoes a conformational change when bound to ATP. D. is directly tethered to DNA polymerase. E. keeps the DNA polymerase on the template. - Answer-C. undergoes a conformational change when bound to ATP. /.During dietary polysaccharide digestion, α(1,4) linkages are cleaved by: A. Glycogen phosphorylase B. Glycogen debranching enzyme C. Phosphoglucomutase D. α-amylase E. Maltase - Answer-D. α-amylase /.During translocation, the ribosome is moved towards the 3' end of the mRNA. In eukaryotes, this requires: A. eEF1α. B. eEF1βγ.