BCMB230ex1f08.doc

Human Physiology Fall 2008 Exam I 1. If red blood cells are placed in a hypertonic solution of NaCl they will: a. shrink b. swell c. dance d. remain the same 2. If red blood cells are placed in a solution that is isoosmotic the cells will: a. shrink b. swell c. remain the same d. change depends on type of solutes 3. Permeability of an epithelial layer cannot be regulated by: a. ion channels b. tight junctions c. transport proteins d. phospholipids 4. Which of the following would increase the rate of diffusion ? a. increase cell permeability b. increase the size of the particles moved c. decrease the size of the concentration gradient d. decrease the temperature 5. Which process is most likely to be involved in helping to produce different proteins from the same gene? a. RNA splicing b. transcription c. translation d. all of the above 6. Interactions between multiple polypeptide chains within a protein act to produce the protein?s: a. primary structure b. secondary structure c. tertiary structure d. quaternary structure 7. Denaturing a protein: a. can be caused by inappropriate pH or temperature b. is always reversible c. is commonly used to regulate function d. all of the above 8. Which of the following is not consistent with an increase in affinity at a binding site? a. increase in covalent bonding between ligand and site b. better physical fit of ligand into the bind site c. increase in ionic or hydrogen bonding between ligand and site d. increased time that ligand is bound to binding site 9. Movement of molecules between the cells of an epithelial layer is called: a. transcellular transport b. paracellular transport c. cotransport d. mediated transport 10. Which of the following is true when the concentration of a single ligand is high: a. decreased affinity b. competition c. saturation d. both a and c 11. The energy source directly used for most cellular activity is: a. ATP b. NADH c. glucose d. all of the above 12. The process by which messenger RNA is used to make a protein is: a. metabolism b. translation c. transcription d. replication 13. Which of the following would not moved by secondary active transport? a. K+ b. bicarbonate ions c. Cl- d. glucose 14. A human red blood cell contains a solution that is approximately 300 mOsm. What will happen if we place a red blood cell in a 300 mM solution of NaCl. a. nothing b. cell swells c. cell shrinks d. no net movement of solute or water 15. Which of the following process show a transport maximum (maximal flux): a. exocytosis b. secondary active transport c. facilitated diffusion d. both b and c 16. A change in a physiological process in an individual due to continued exposure to a changed environmental condition is called: a. feed forward regulation b. adaptation c. acclimatization d. autocrine reflex 17. Which of the following types of stimuli can be used to signal opening or closing of ion channels? a. electrical (voltage) b. chemicals (ligands) c. mechanical (contact) d. all of the above 18. The tendency of the human body to maintain a constant internal environment is called: a. negative feedback b. positive feedback c. homeostasis d. metabolism 19. Small polar molecules can pass through the plasma membrane if: a. appropriate membrane proteins are present b. a concentration gradient is present c. the cell requires the molecule to function d. appropriate receptors for endocytosis are present 20. The direction of the reaction in a reversible reaction is determined by: a. enzymes b. activation energy c. the relative concentrations of the reactants and products d. all of the above 21. If oxygen is present each glucose molecule used in cellular respiration results in the net formation of: a. 6CO2, 6H2O, and 38ATP b. 2 pyruvate and 2 ATP c. 2 lactate and 2 ATP d. 2 pyruvate, 4ATP, and 2NADH 22. Substrate phosphorylation to produce ATP occurs in a. glycolysis b. Krebs cycle c. oxidative phosphorylation d. both a and b 23. Deamination a. results in the ultimate production of urea b. is necessary before an amino acid to be used in cellular respiration c. is necessary before an amino acid to be transformed into carbohydrate or fat d. all of the above 24. Inhibiting cyclooxygenase would decrease the production of: a. phospholipase A2 b. arachidonic acid c. thromboxanes d. leukotrienes 25. Enzymes a. influence the direction of a chemical reaction b. typically act on multiple substrates c. are often sensitive to large changes in pH or temperature d. always require the use of ATP 26. Membrane receptors for chemical messengers act by: a. changing shape when the messenger binds b. changing the permeability of the cell membrane c. activating enzymes d. all of the above are possible 27. A phosphatase: a. phosphorylates another protein b. is typically active all the time c. breaks G proteins into active subunits that activate other proteins d. activates transcription factors to produce a new protein 28. Beta oxidation a. produces NADH for oxidative phosphorylation b. removes 2 carbon segments from fatty acid chains c. directly produces ATP d. both a and b are true 29. Feed forward regulation a. is a form of positive feedback b. requires a kinase c. results in a response before homeostasis is disrupted d. is a form of negative feedback 30. Which of the following is not produced by oxidative phosphorylation? A. water b. NAD c. ATP d. carbon dioxide 31. Phospholipase C a. produces DAG b. is activated by a G protein c. is a membrane protein d. all of the above 32. Which of the following does not act as a second messenger? a. adenyl cyclase b. cAMP c. IP3 d. calcium 33. A solution that contains 150mosm of glucose and 300mOsm of glycerol is: For this cell glycerol is a penetrating solute and glucose is nonpenetrating. a. hypotonic b. hyperosmotic c. hypertonic d. both a and b 34. If a transport maximum for glucose has been reached what can the cell do to increase the amount of the glucose moved across the membrane? a. nothing can be done to increase the rate of glucose transport b. activate inactive glucose transporters present in the membrane c. increase transcription of the gene for the glucose transporter d. both b and c could be possible 35. Glycolysis produces: a. 6 NADH b. 10 NADH c. 2NADH d. 10 NAD 36. Conversion of pyruvate to acetylCoA: a. uses oxygen b. produces NAD c. produces ATP d. produces carbon dioxide 37. In an enzyme regulated reaction the speed of a reaction can be increased by: a. increasing the affinity of the active site for the substrate b. increasing the concentration of the substrate c. increasing the number of enzymes present d. all of the above 38. Which of the following moves through the plasma membrane without using a transmembrane protein? a. sodium ions b. fatty acids c. amino acids d. water 39. Which of the following cannot be moved against its concentration gradient? a. amino acids b. Na+ c. Ca+2 d. fatty acids 40. Transcellular transport across a cell layer a. always requires ATP b. is controlled by membrane proteins c. is poorly regulated and largely dependent on particle size d. both a and b 41. Which protein binds calcium as part of a signal transduction mechanism? a. a tyrosine kinase b. a JAK kinase c. calmodulin d. all of the above 42. Which protein acts by disassembling into active subunits? a. Na/K ATPase b. myosin c. GTP d. G proteins Which mechanism can be used to decrease plasma membrane permeability to Cl- : a. an increase in transcription of the gene for Cl- channels b. opening more Cl- channels c. increase the degradation of Cl- channels d. all of the above 44. Which of the following is an advantage of multiple step signal transduction pathway? a. amplification of the signal b. integration and coordination of the response c. providing lots of details to keep physiology students busy d. both a and b 45. In which of the following is an enzyme activity and a binding site part of the same protein? membrane protein? a. ligand gated channel b. tyrosine kinase c. JAK kinase d. both a and b 46. Which of the following processes is typically regulated to change the level of active proteins within a cell? a. denaturation b. post translational modification c. activity of a phosphatase d. replication 47. If both ligand A and ligand B can bind to the same site on a protein which of the following would increase the binding of ligand A. a. decrease the concentration of ligand B b. increase the protein?s affinity for ligand A c. increase the number of binding sites (proteins) d. all of the above 48. Enzymes act to increase reaction rates by: a. increasing substrate surface area b. increasing temperature c. decreasing activation energy d. all of the above Movement of amino acids down a concentration gradient and across a cell membrane is by: a. primary active transport b. secondary active transport c. facilitated diffusion d. simple diffusion 50. Movement of glucose against a concentration gradient and across a cell membrane is by: a. primary active transport b. secondary active transport c. facilitated diffusion d. simple diffusion