311Cexam2oct07-2 - Bio 311C Exam 2 October 23, 2007 [points...

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Bio 311C Exam 2 Name______________________________________ October 23, 2007 [points 50: MC + 50 written; 6 pages] UT EID____________________________________ For questions 1-25 choose the one correct answer, write it here and also on the scan form. 1_______The presence of which gradients is necessary to cause the osmotic movement of water across a membrane? (A) total electrical charge gradient (regardless of which specific type of ions); (B) total solute gradient (regardless of which specific type of solutes); (C) total H+ ion (pH) gradient; (D) two of these will affect the movement of water; (E) all three of these will affect the movement of water. 2_______Which one of the following is false about the sodium-potassium pump? (A) it uses ATP for energy; (B) it transports both Na+ and K+ ions against their gradients; (C) it is a trans-membrane protein, not a peripheral protein; (D) it maintains the ion gradients that make it possible for an action potential to occur; (E) it is the main reason the inside of a cell is much more negative than the outside. 3_______An artificial membrane separates solution A from solution B. The membrane contains passive channels for all three of these types of ions. In the initial movements of these ions across the membrane (way before they reach equilibrium), which ions will start to move and in what directions? (A) only Na+ ions move, from A to B (B) Na+ and K+ ions move from A to B (C) Na+ and Cl- ions move from A to B (D) Na+ from A to B and Cl- from B to A (E) Na+ from A to B and K+ from B to A 4_______If there were no ion channels in the artificial membrane and the ion concentrations were as above, the net direction of water would be which? (A) no net movement (equal in both directions); (B) from A to B through the phospholipid bilayer; (C) from B to A through the phospholipid bilayer; (D) from A to B only if protein channels for water were present; (E) from B to A only if protein channels for water were present. 5_______Rank, from largest to smallest, the size of the largest particle that could pass from cell to cell through these three cell junctions: X. gap junctions; Y. plasmodesmata; Z. tight junctions. (A) X (largest), Y, Z; (B) Z, Y, X; (C) Y, Z, X; (D) Z, X, Y; (E) Y, X, Z. 6______In comparison to the same ball at the top of a hill, a ball at the bottom of the hill has (A) lower stability; (B) lower chemical bond energy; (C) greater entropy; (D) more order; (E) less randomness. 7_______The energy that is used directly by the proton-sucrose symport to move sucrose into cells against its concentration gradient is from which of these? (A) sucrose hydrolysis to glucose; (B) ATP hydrolysis to ADP + P; (C) H+ ions diffusing down their concentration gradient; (D) sucrose molecules diffusing down their concentration gradient; (E) osmosis. 8_______Most of the ATP used by a
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This note was uploaded on 08/18/2011 for the course BIO 1406 taught by Professor Bostic during the Spring '09 term at Austin Community College.

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311Cexam2oct07-2 - Bio 311C Exam 2 October 23, 2007 [points...

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