PracticeExam2 - Bio 311C Buskirk Exam 2 October 30, 2006...

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Bio 311C Buskirk Exam 2 October 30, 2006 For questions 1-22, write the correct answer on this paper and also on the scan form with #2 pencil. 1________How does an enzyme catalyze a reaction? (A) by supplying the energy to speed up a reaction; (B) by lowering the energy of activation of a reaction; (C) by changing the G of a reaction; (D) by serving as additional reactant used in the reaction; (E) by changing a reaction from endergonic to exergonic. 2_______In membrane system A, the sodium ion concentration [Na+] is about equal on both sides. In membrane system B, one side has a higher sodium ion concentration than the other. Which one of these is true? (A) system B has greater entropy than A; (B) system B has greater stability than A; (C) system B has greater bond energy than A; (D) system B has greater free energy than A; (E) system B has greater pH difference than A. 3________ Which of these is true and also is the difference between a carrier protein and a channel protein? (A) a carrier protein has a fluid-filled pore that opens for transport; (B) a channel protein uses ATP to pump ions through a fluid-filled pore; (C) a carrier is used in facilitated transport and a channel is not; (D) a channel is a trans-membrane protein and a carrier is not; (E) a carrier changes its conformation (shape) in order to move substances across a membrane and a channel does not. 4________Which best describes the action of the sodium-potassium (Na+/K+) pump in transporting substances across a membrane? (A) it transports one substance down its concentration gradient and one against its concentration gradient, using no ATP; (B) it transports one substance down its concentration gradient and one against its concentration gradient, using ATP; (C) it transports both substances against their concentration gradients, using no ATP; (D) it transports both substances against their concentration gradients, using ATP; (E) it transports both substances down their concentration gradients, in opposite directions. 5_________Which of the following is most likely to decrease the amount of diffusion of a substance INTO a cell? (A) increased cell surface area; (B) increased temperature; (C) decreased particle size of substance; (D) decreased concentration of substance inside cell; (E) decreased electrical charge difference across the membrane. 6____ This graph shows rate of movement plotted against solute concentration for the facilitated diffusion of an amino acid into a cell. The rate of movement plateaus: (A) when more amino acid leaves the cell than enters it (B) because the cell no longer requires this particular amino acid (C) because more solute is present than can be handled at once by the transport proteins (D) because the cell runs low on ATP to provide energy (E) because there is no longer an ion or electrochemical gradient across the cell membrane 7________The inside of a neuron cell is negative, and the sodium ion concentration outside is higher than inside. When passive transport proteins for sodium ions OPEN, which will happen? (A) sodium
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This test prep was uploaded on 03/19/2008 for the course BIO 311C taught by Professor Satasivian during the Fall '08 term at University of Texas at Austin.

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PracticeExam2 - Bio 311C Buskirk Exam 2 October 30, 2006...

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