Đề Thi Giữa Kỳ Sinh Hóa Dược (EN)

MID-TERM EXAM: HUMAN PHYSIOLOGY & IMMUNOLOGY SEPTEMPER 15th, 2015 TIME 40 minutes Students answer directly on these pages Name of student Student number Which of the following statements best describes pharmacodynamics? A The study of how drugs reach their target in the body and how the levels of a drug in the blood are affected by absorption, distribution, metabolism and excretion B The study of how drugs can be designed using molecular modelling based on a drug's pharmacophore C The study of how a drug interacts with its target binding site at the molecular level D The study of which functional groups are important in binding a drug to its target binding site and the identification of a pharmacophore Which of the following statements best describes pharmacokinetics? A The study of how drugs reach their target in the body and how the levels of a drug in the blood are affected by various factors B The study of how drugs can be designed using molecular modelling based on a drug's pharmacophore C The study of how a drug interacts with its target binding site at the molecular level D The study of which functional groups are important in binding a drug to its target binding site and the identification of a pharmacophore Which of the following statements is false? A Drug targets are normally macromolecules B Drugs are generally organic molecules C Drugs are generally smaller than drug targets D Drugs usually act by forming covalent bonds with drug targets Which of the following statements is false with respect to a binding site? A It contains binding regions B It is usually hydrophilic in nature C It is normally a hollow or cleft on the surface of the drug target D It is part of a macromolecule that acts as a drug target Which of the following statements is not true regarding the active site of an enzyme? A An active site is normally on the surface of an enzyme B An active site is normally hydrophobic in nature C Substrates fit into active sites and bind to functional groups within the active site D An active site contains amino acids which are important to the binding process and the catalytic mechanism Which of the following terms refers to the process by which a substrate binds to an active site and alters the shape of that active site? A Moulded fit B Intermolecular bonding C Lock and key theory D Induced fit Which of the following statements is not true about receptors? A Most receptors are proteins situated inside the cell B Receptors contain a hollow or cleft on their surface which is known as a binding site C Receptors bind chemical messengers such as neurotransmitters or hormones D Receptors not catalyse reactions on chemical messengers Which of the following statements is not true regarding the binding site of a receptor? A The binding site is normally a hollow or cleft in the surface of an receptor B The binding site is normally hydrophilic in nature C Chemical messengers fit into binding sites and bind to functional groups within the binding site D The binding site contains amino acids which are important to the binding process Which of the following statements best describes an induced fit? A The process by which a binding site alters shape such that it is ready to accept a chemical messenger B The process by which a chemical messenger adopts the correct binding conformation before entering a binding site C The process by which binding of a chemical messenger to a binding site alters the shape of the binding site D The process by which a binding site alters the shape of the chemical messenger into the binding conformation before binding 10 There is a fine balance required for the binding interactions of a neurotransmitter with its receptor Which of the following statements best expands on this statement? A It is important that the binding interactions involve a mixture of van der Waals interactions, hydrogen bonds and ionic bonds since neurotransmitters have different functional groups B The binding interactions must be of the correct nature to match the functional groups of the neurotransmitter and the functional groups in the binding site C The binding interactions must be sufficiently strong that the neurotransmitter binds long enough to have an effect, but not too strong in case the neurotransmitter remains permanently bound D There must be the correct balance of hydrophilic and hydrophobic interactions to ensure that the chemical messenger can enter a hydrophobic binding site 11 Which of the following descriptions best describes a competitive enzyme inhibitor? A A drug that binds to an active site and undergoes a reaction B A drug that binds to an active site and inhibits the enzyme, but which is displaced by increasing the concentration of substrate C A drug that binds to an active site and inhibits the enzyme, but which is not displaced by increasing the concentration of substrate D A drug that binds to a different binding site from the active site and affects the activity of the enzyme 12 Which of the following descriptions best describes an allosteric inhibitor? A A drug that binds to an active site and undergoes a reaction B A drug that binds to an active site and inhibits the enzyme, but which is displaced by increasing the concentration of substrate C A drug that binds to an active site and inhibits the enzyme, but which is not displaced by increasing the concentration of substrate D A drug that binds to a different binding site from the active site and affects the activity of the enzyme 13 Which of the following properties of a drug is most likely to result in a minimum of side effects? A Good oral absorption B Fast metabolism C Target selectivity D Target affinity 14 What sort of agent binds to a binding site that is next to the binding site for an endogenous chemical messenger, and sterically blocks the messenger from binding? A An agonist B An allosteric antagonist C An inverse agonist D An antagonist acting by the 'umbrella' effect 15 What sort of agent binds to a receptor using a different binding site from that used by the endogenous chemical messenger, and distorts the binding site such that the endogenous messenger cannot bind? A An agonist B An allosteric antagonist C An inverse agonist D An antagonist acting by the 'umbrella' effect 16 Which of the following is not a necessary requirement when designing an agonist? A The presence of the correct binding groups B The correct size and shape of the molecule C The correct relative orientation of the binding groups D The identical functional groups present in the endogenous chemical messenger 17 Which of the following descriptions most accurately describes binding sites and binding regions? A A binding site is part of a binding region B A binding region is part of a binding site C A binding region is the same as a binding site D A binding region is on a drug whereas a binding 18 Which of the following statements best describes the potency of a drug? A The maximum biological effect resulting from a drug binding to its target B The measure of how strongly a drug binds to a receptor C.The lifetime of the drug in the body D The amount of drug required to produce a defined biological effect 19 Which of the following symbols represents the concentration of a drug required to produce 50% of a maximum possible effect? A IC50 B Ki C Kd D EC50 20 Which of the following statements best describes the efficacy of a drug? A The maximum biological effect resulting from a drug binding to its target B The measure of how strongly a drug binds to a receptor C The amount of drug required to produce a defined biological effect D The lifetime of the drug in the body 21 Which of the following terms applies to the study of how a drug interacts with its target binding site at the molecular level? A Pharmacokinetics B Structure based drug design C Pharmacodynamics D Structure-activity relationships 22 Which of the following terms best describes the study of how drugs reach their target in the body and how the levels of a drug in the blood are affected by absorption, distribution, metabolism, and excretion? A Pharmacokinetics B Structure based drug design C Pharmacodynamics D Structure-activity relationships 23 Which of the following descriptions best fits an agonist? A A compound that has the same effect on a receptor as the endogenous chemical messenger B A compound that binds to a receptor, and activates it, but to a lesser extent than the endogenous chemical messenger C A compound that binds to a receptor fails to activate it and prevents the endogenous chemical messenger from binding D A compound that binds to a receptor fails to activate it and leads to a drop in inherent biological activity 24 Which of the following descriptions best fits an antagonist? A A compound that has the same effect on a receptor as the endogenous chemical messenger B A compound that binds to a receptor, and activates it, but to a lesser extent than the endogenous chemical messenger C A compound that binds to a receptor fails to activate it and prevents the endogenous chemical messenger from binding D A compound that binds to a receptor fails to activate it and leads to a drop in inherent biological activity 25 Which of the following is not a regulatory protein used a drug target A Receptors B Ion channels C Carrier molecules and/or transporters D Hormones E Enzymes 26 Which of the following statements is true regarding amphotericin B? A The framed region is a hydrophilic region that interacts with the phospholipid bilayer of cell membranes by van der Waals interactions B Several molecules of amphotericin self-assemble to form a hydrophobic tunnel through the cell membrane The tunnel interior is lined with non-polar functional groups C The amphotericin molecule is the ideal length to span the cell membrane D Amphotericin acts as an antifungal drug by allowing the uncontrolled passage of ions and water across the cell membrane 27 The enzyme system responsible for the metabolism of most drugs is A P-glycoprotein B alkaline phosphatase C cytochrome P-450 D HMG-CoA 28 Nonlinear pharmacokinetics means A drug serum concentrations decrease in a straight line when plotted on a concentration-time graph B drug serum concentrations decrease in a straight line when plotted on a log concentration-time graph C steady-state drug serum concentrations change proportionally to dose D steady-state drug serum concentrations change nonproportionally to dose 29 Linear pharmacokinetics means A drug serum concentrations decrease in a straight line when plotted on a concentration-time graph B drug serum concentrations decrease in a straight line when plotted on a log concentration-time graph C steady-state drug serum concentrations change proportionally to dose D steady-state drug serum concentrations change nonproportionally to dose 30 True statement(s) concerning competitive inhibition A competitive in addition is based on reversible drug/antagonist binding at receptor sites B with competitive inhibition, the dose-effects curve the shifted to the left C with competitive inhibition, maximal drug effect cannot be obtained, even at high agonist concentrations D all the above 31 Drug targeted at receptors A Inhibitors & Activators C Agonists & Antagonists B Competitive Facilitators D Receptor Mediators 32 What is bioavailibility A Availability of a drug in the natural environment B Quantity of drug remaining after one half life C Rate that the drug is made available by the liver D Rate and quantity of a drug absorbed into the bloodstream E Quantity of drug remaining after the first metabolism 33 Which of the following terms describes how much of a drug will be available in the body to produce a pharmacoloic response after it is administered? A liberation B bioavailability C biotransformation D bioequivalence 34 Pharmacokinetics involves all the following concepts except one Which one is the exception? A Metabolism B Elimination C Binding D Distribution E Absorption 35 Which of the following route of administration is used in emergency situations? A Intravenous B Rectal C Sublingual D Oral 36 Which of the following terms describes the actions of a tablet on the body after ingestion and absorption? A Pharmacokinetics B Pharmacodynamics C Pharmacology D Toxicology 37 Which of the following definitions best describes the ED50 of a drug? A The dose of a drug required to produce 50% of a maximum effect B The dose of a drug required to produce a measurable effect in 50% of the animals tested C The ratio of LD50 to ED50 D The dose of a drug required to kill 50% of a group of animals 38 Which of the following definitions best describes the LD50 of a drug? A The dose of a drug required to produce 50% of a maximum effect B The dose of a drug required to produce a measurable effect in 50% of the animals tested C The ratio of LD50 to ED50 D The dose of a drug required to kill 50% of a group of animals 39 Which of the following statements is the closest description of Phase I metabolism? A Reactions which add a polar molecule to a functional group already present on a drug or one of its metabolites B Reactions which occur in the blood supply C Reactions which occur in the gut wall D Reactions which add a polar functional group to a drug 40 Which of the following statements is the closest description of Phase II metabolism? A Reactions which add a polar molecule to a functional group already present on a drug or one of its metabolites B Reactions which occur in the blood supply C Reactions which occur in the gut wall D Reactions which add a polar functional group to a drug 41 What is the mode of action for the anthracycline anticancer agents (ex: Doxorubicin)? A Alkylating agents B Chain cutting agents C Antisense agents D Intercalating agents 42 The following agent is used for the treatment of testicular and ovarian cancers Which of the following statements is untrue regarding the above structure? A The chlorine groups are displaced before the drug becomes active B Intrastrand cross linking of DNA results from the action of the agent C Base pairing between adenine and thymine is disrupted by the agent D The compound acts as a metallating agent 43 Which of the following binding interactions is likely to be the most important initial interaction when a drug enters a binding site? A Hydrogen bond B van der Waals interactions C Ionic D Induced dipole-dipole interactions 44 What is meant by a binding site? A The area of a macromolecular target that is occupied by a drug when it binds B The portion of the drug to which a drug target binds C The functional groups used by a drug in binding to a drug target D The bonds involved in binding a drug to its target 45 Which of the following statements is true? A Drugs and drug targets generally have similar molecular weights B Drugs are generally smaller than drug targets C Drugs are generally larger than drug targets D There is no general rule regarding the relative size of drugs and their targets